The graph shows the motion of a cyclist.
Calculate;
a) The acceleration in the first 20 s.
b) The acceleration between 20 and 30s.
c) The acceleration in the last 10 s.
d) The distance travelled by the cyclist when he was moving at a constant speed?
Show working.
Answer:
A. 0.5m/s².
B. –0.5m/s².
C. –0.5m/s².
D. 100m.
Explanation:
A. Determination of the acceleration in the first 20s.
Initial velocity (u) = 0
Final Velocity (v) = 10m/s
Time (t) = 20secs.
Acceleration (a) =..?
Acceleration = change in Velocity /time
a = (v – u)/t
a = (10 – 0)/20 = 10/20
a = 0.5m/s²
Therefore, the acceleration of the cyclist in the first 20secs is 0.5m/s²
B. Determination of the acceleration between 20 and 30s. This can be obtained as follow:
Initial velocity (u) = 10m/s
Final Velocity (v) = 5m/s
Time (t) = 30 – 20 = 10s
Acceleration (a) =..?
Acceleration = change in Velocity /time
a = (v – u)/t
a = (5 – 10)/10 = –5/10
a = –0.5m/s²
Therefore, the acceleration of the cyclist between the 20 and 30secs is
–0.5m/s².
C. Determination of the acceleration in the last 10s.
Initial velocity (u) = 5m/s
Final Velocity (v) = 0
Time (t) = 10s
Acceleration (a) =..?
Acceleration = change in Velocity /time
a = (v – u)/t
a = (0 – 5)/10 = –5/10
a = –0.5m/s²
Therefore, the acceleration of the cyclist between the last 10secs is
–0.5m/s².
D. Determination of the distance travelled by the cyclist when he was moving at a constant speed.
Velocity (v) = 5m/s
Time (t) = 50 – 30 = 20secs
Displacement (d) =?
Velocity = Displacement /Time
v = d/t
5 = d/20
Cross multiply
d = 5 x 20
d = 100m
Therefore, the distance travelled by the cyclist at constant speed is 100m
A closed-pipe resonator has a length of 1.73 m. The frequency of its second harmonic if the speed of sound is 343 m/s is: a)49,5 Hz b)99.13 Hz c)20.6 Hz d)72 Hz
Answer:
There is no answer, since a closed-pipe resonator can NOT have a second harmonic. However, if you were to plug the pipe length and the speed of sound into the closed-pipe equation anyway you would get 49.56 as your fundamental frequency, which means that 99.13 would be your "plug and play" 2nd harmonic.
Explanation:
List two things you should not do when encountering a funeral procession?
party and being happy..........
A German scientist, George Ohm, discovered the relationship between current, voltage, and resistance. This became known as Ohm's law. According to Ohm’s law, if V is voltage, I is current, and R is resistance, their relationship is expressed by the equation
Answer:
I=V/R is the formula for ohm's law .
Explanation: I=V/R is the formula for ohm's law
Answer:
I= V/R
Explanation:
The equation, i = v/r, tells us that the current, i, flowing through a circuit is directly proportional to the voltage, v, and inversely proportional to the resistance, r. (Study.com)
Describe The energy conversions that occur when coal is formed, and then burned to produce thermal energy.
Answer:
When energy contained in coal is turned into heat, and then into electrical energy. As boiling water heated by the burning coal is cooled, steam forges from these cone-shaped cooling towers.
How much energy sun release in the form of radiation
Answer: Hope this is right
4 x 10^26 watts every second.
Explanation:
The sun, like all active stars, is a massive hydrogen-burning furnace producing huge amounts of light, heat and radiation, about 4 x 10^26 watts every second.
what is the defination o
f temperature
Answer: The degree or intensity of heat present in a substance or object, especially as expressed according to a comparative scale and shown by a thermometer or perceived by touch.
One of the earliest forms of load-bearing construction is the ____ method of construction.
Answer:
the materials most often used to construct load bearing walls in large building are concrete ,block or brick . load bearing walls are one of the earliest forms of construction
Explain Why a flying aeroplane has more Kinetic Energy than a flying insect?
Answer:
Why do insects fly so high?
Because the angle of attack is so high, a lot of momentum is transferred downward into the flow. These two features create a large amount of lift force as well as some additional drag. The important feature, however, is the lift.
Why an Aeroplane flying has kinetic
A flying aeroplane has potential energy has it flies above the ground level. And since the aeroplane is flying motion is associated with it and thus possesses kinetic energy. Hence a flying aeroplane has both potential and kinetic energ
Explanation:
Who is prime minister of india
His name is
Narendra Modi
Answer:
Hey!
*its kinda the wrong topic but ill answer anyway!!!*
The Prime Minister of India is...
Narendra ModiExplanation:
HOPE THIS HELPS!!
Suppose that you walk 15 meters at 30 degrees as measured from the East. Then you walk another 25 meters at 60 degrees from the East what is your net displacement
Answer:
The net displacement is
[tex]R= \sqrt{A^2+B^2+2AB \cos \theta}[/tex]
[tex]=\sqrt{15^2+25^2+2AB \cos 30^\circ} \\\\=\sqrt{225+625+ \cos30^0} \\\\=38.7m[/tex]
Explanation:
Suppose that you walk 15 meters at 30 degrees as measured from the East. Then you walk another 25 meters at 60 degrees from the East what is your net displacement
Given data
A = 15 m
B = 25 m
Angle between the vectors A and B is θ = 30°
The net displacement is
[tex]R= \sqrt{A^2+B^2+2AB \cos \theta}[/tex]
[tex]=\sqrt{15^2+25^2+2AB \cos 30^\circ} \\\\=\sqrt{225+625+ \cos30^0} \\\\=38.7m[/tex]
3 The atmospheric pressure on a particular
day was measured as 750 mmHg.
Express this in nm-2? ( Assume densityof
mercury is 136ookgm3 and g =10Nkg-1'?
Answer:
102000N/m2
This is the same as 102KN/m2 (where K = 10^3):
Explanation:
The expression 750 mmHg means 750 height the atmospheric pressure will cause mercury to be suspended due to gravity.
If we brought another fluid under investigation under the influence of the atmospheric pressure the height would be different)
Note that 750 mmHg would be the same as 750/1000 m Hg ( when we convert the mm to m)
0.75mHg
Now to get the pressure in N/m2.
We multiply the height of mercury by the density by the acceleration due to gravity.
This is expressed mathematically thus;
H×d × g ; let d- denote density
Hence we have;
H×d × g = 0.75 × 13600 × 10= 102000N/m2;
Now let's look at the flip.side assuming you don't know the formula for what you require you could use the idea of Unit derivation ;
The unit of interest is N/m2
The unit of height is m
The unit of density is kg/m3
The unit of g is Nkg-1
We would observe if we multiply
m × N/Kg × Kg/m3
We would have (m× N × Kg)/(kg×m3)
Kg cancels out, m cancels out one m from me remaining m2.
Hence our unit becomes N/m2
Note : the unit for density is wrongly expressed remember density is Mass/ volume and their units are respectively kg/m3
The atmospheric pressure on a particular day was measured as 750 mm of Hg. this would be in 102000 N/m² ( By Assuming the density of
mercury is 13600 kg/m3 and g =10Nkg-1
What is pressure?The total applied force per unit of area is known as the pressure.
The pressure depends both on externally applied force as well the area on which it is applied.
The mathematical expression for the pressure
Pressure = Force /Area
the pressure is expressed by the unit pascal or N /m²
As given in the problem The atmospheric pressure on a particular day was measured as 750 mm of Hg.
Atmospheric pressure is measured by the formula
P = ρgh
where ρ is the density of the mercury
g is the acceleration due to gravity
h is the height of the liquid
By substituting the respective values
P = 13600*10*(750/1000)
P = 102000 N/m²
Thus, the atmospheric pressure would be 102000 in N/m².
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describe three factors that influence the location of rural settlement
Explanation:
presence of food, water ,etc
Explanation:
here is five all you have to do is just pick
A rocket is launched from atop a 101 foot cliff with an initial velocity of 116 ft/s.
\a. Substitute the values into the vertical motion formula h(t) = -16t2 + vt + h0 . Let h(t) = 0
b. How long will the rocket take to hit the ground after it is launched? Round to the nearest tenth of a second.
Answer:
A. 16t2 -116t -101=0 B. 8.0s
Explanation:
Known parameters from the question:
Height of Cliff,h0 = 101ft
Velocity of rocket ,v= 116ft/s.
1.Substituting the above to the above formula we have;
h(t) = -16t2 + vt + h0
Since h(t) =0, it means the rocket is falling towards the ground, when it gets to the ground when it's at rest the height h(t) = 0m
{Note the rocket is launched from the height of the Cliff so that would be the initial height of the rocket,h0}
2.Substituting into h(t) = -16t2 + vt + h0
We have;
0 = -16t2 + 116t + 101=> 16t2 -116t -101=0
Using formula method for solving quadratic equation we have;
t = -(-116)+_√[(-116)^2 -( 4× 16 ×-101]/ (2× 16)
t = [116 +_(141.1382)]/32
t = (116 -141.1382)/32 or (116 +141.1382)/32
-0.786s or 8.036s
-0.8s or 8.0s to the nearest tenth.
Now time cannot be negative in real life situation hence the time is 8.0s
Note : the general equation of a quadratic equation with variable t is given below;
at2 + bt + c=0
Formula method for quadratic equation is :
t =( -b+_√[(b^2 -( 4× a×c)] ) / (2× a)
What happens to a sound wave as air temperature decreases?
A. The wave returns to rest a position
B. The wave’s speed decreases
C. Air particles push harder on the wave
D. The waves speed increases
Answer:
Explanation:
goes down as the temperature decreases, and vice versa. Sound's frequency is independent of temperature, while its speed is directly proportional to temperature. Heat, like sound, is a form of kinetic energy. Molecules at higher temperatures have more energy, thus they can vibrate faster. Since the molecules vibrate faster, sound waves can travel more quickly. ... This is faster than 331 meters per second, which is the speed of sound in air at freezing temperatures.
hope this helps!!!!
Sound waves travel more fastly in hot air , since particles in atmosphere gets more energetic in higher temperature. Hence, as the temperature decreases, the wave’s speed decreases.
What is sound waves ?Sound waves are mechanical waves passing through a medium. Sound waves are longitudinal where, the oscillation of particles is along the direction of wave propagation.
Compression waves, which at a microscopic scale rely on molecules transmitting energy one to another, are used to convey sound through the air.
Higher temperatures produce more energetic air molecules, which vibrate more rapidly. As a result of the molecules colliding with one another, the sound waves can move more quickly.
Therefore, as the temperature decreases, the speed of sound wave decreases. Thus, option B is correct.
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Mass is the amount of what
Answer:
Mass is the amount of matter in a substance.
Explanation:
The basic SI unit for mass is the kilogram (kg).
18. Which does not affect the strength of an electromagnet?
A the current in the solenoid
B the temperature of the coil
OC the number of loops in the coil
D the type of ferromagnetic core
Answer:
The temperature does not affect the strength of a magnetExplanation:
An electromagnet is obtained by winding an insulated wire round a soft iron rod with the wire ends connected to a DC source. such magnets have temporary magnetic properties which disappears with time as the current supply is cut off.
Furthermore the strength off an electromagnet
increases as current increasesincreases as the number of turns increasesthe type of magnetic core is highly essential as an iron core will do batter than a silver core
iv. The lift raises a car of mass 850 kg to a height of 2.1 m. It uses a force of 8330 N and takes 4 seconds to raise the car. What is the power of the lift? (1 point)
Answer:
Power is 4373.25 W
Explanation:
We have,
The lift raises a car of mass 850 kg to a height of 2.1 m. It uses a force of 8330 N and takes 4 seconds to raise the car. It is required to find the power of the lift. Power is equal to the rate at which the work is done. So,
[tex]P=\dfrac{Fd}{t}\\\\P=\dfrac{8330\times 2.1}{4}\\\\P=4373.25\ W[/tex]
So, the power of the lift is 4373.25 W.
A negative test charge experiences a force to the right as a result of an electric field. Which is the best conclusion to draw based on this description?
a.The electric field points to the left because the force on a negative charge is opposite to the direction of the field.
b.The electric field points to the right because the force on a negative charge is in the same direction as the field.
c.No conclusion can be drawn because the sign of the charge creating the field is unknown.
d.No conclusion can be drawn because the amount of charge on the test charge is unknown.
OPTION B IS THE ANSWER
Answer:
The real answer is A 2023 answer -_-
Explanation:
what microscope creates a two dimensional image
Answer:
Compound microscope
Explanation:
Answer:
Compound microscope
Explanation:
Compound microscope is the kind of optical microscope which creates a two dimensional image when the visible light is illuminated it magnifies the object and produces its image.
In some creatures, bioluminescence transforms
energy
energy into
OA) heat; light
OB) light; heat
OC) chemical potential; light
OD) light; chemical potential
Answer:
Hey!
Your answer would be option B. Light; heat...
Explanation:
In bioluminescent organisms, the energy is transformed int light energy and less then 20% of the total energy is put into Thermal Radiation!
HOPE THIS HELPS!!
10) Um viajante, ao desembarcar no aeroporto de Londres, observou que o valor da temperatura do ambiente na escala Fahrenheit é o quíntuplo do valor da temperatura na escala Celsius. Calcule essa temperatura
Answer:
The observed temperature was 10º Celsius or 50º Fahrenheit.
Explanation:
The traveler observed that the temperature in Fahrenheit is five times the value of the temperature in Celsius, therefore:
[tex]F = 5*C[/tex]
A Fahrenheit temperature relates to a Celsius one by the following expression:
[tex]F = \frac{9}{5}*C + 32[/tex]
Using the second expression on the first, we can solve for the temperature in Celsius, this is done below:
[tex]\frac{9}{5}*C + 32 = 5*C\\\frac{9}{5}*C - 5*C = -32\\\frac{9*C - 25*C}{5} = -32\\\frac{-16*C}{5} = -32\\-16*C = -32*5\\-16*C = -160\\C = \frac{-160}{-16} = 10\º\text{C}\\F = 5*C = 5*10 = 50\º\text{F}[/tex]
The observed temperature was 10º Celsius or 50º Fahrenheit.
A non-uniform rod 60cm long and weighs 32N is balanced at the 45cm mark. A load of 2N is hung on the zinc rod at the 25cm mark. Where must a second knife-edge be placed to balance the zinc rod horizontally
Answer:
The second knife-edge must be placed 46.2 cm from the zero mark of the rod.
Explanation:
From the law of equilibrium, ΣF = 0 and ΣM = 0.
Let R be the reaction at the knife edge. Since the weight of the rod and zinc load act downward, and we take downward position as negative
-32 N - 2 N + R = 0
-34 N = -R
R = 34 N
Also, let us assume the knife-edge is x cm from the zero mark. Taking moments about the weight and assuming the knife-edge is right of the weight of the rod. Taking clockwise moments as positive and anti-clockwise moments as negative,
-(45 - 25)2 + (x - 45)R = 0
-(20)2 + (x - 45)34 = 0
-40 = -(x - 45)34
x - 45 = 40/34
x - 45 = 1.18
x = 45 + 1.18
x = 46.18 cm
x ≅ 46.2 cm
The second knife-edge must be placed 46.2 cm from the zero mark of the rod.
A 4.0 kg block is initially at rest on a frictionless, horizontal surface. The block is moved 8.0 m by the application of a constant 10.0 N horizontal force. If the block slides into a fixed horizontal spring and comes to rest when the spring is compressed a distance of x=0.25m. Determine the spring constant of the fixed horizontal spring. Show all formula with substitutions and units.
Answer:
k = 2560 N/m
Explanation:
To find the spring constant, you take into account that all the kinetic energy of the block becomes elastic potential energy in the spring, when the block compressed totally the spring:
[tex]K=U\\\\\frac{1}{2}mv^2=\frac{1}{2}kx^2[/tex]
m: mass of the block = 4.0kg
v: velocity of the block just before it hits the spring
x: compression of the spring = 0.25m
k: spring constant = ?
You solve the previous equation for k:
[tex]k=\frac{mv^2}{x^2}[/tex] (1)
Then, you have to calculate the velocity v of the block. First, you calculate the acceleration of the block by using the second Newton law:
[tex]F=ma[/tex]
F: force over the block = 10.0N
a: acceleration
[tex]a=\frac{F}{m}=\frac{10.0N}{4.0kg}=2.5\frac{m}{s^2}[/tex]
With this value of a you can calculate the final velocity after teh block has traveled a distance of 8.0m:
[tex]v^2=v_o^2+2ad[/tex]
vo: initial velocity = 0m/s
d: distance = 8.0m
[tex]v=\sqrt{2ad}=\sqrt{2(2.5m/s^2)(8.0m)}=6.32\frac{m}{s}[/tex]
Now, you can calculate the spring constant by using the equation (1):
[tex]k=\frac{mv^2}{x^2}=\frac{(4.0kg)(6.32m/s)^2}{(0.25m)^2}=2560\frac{N}{m}[/tex]
hence, the spring constant is 2560 N/m
True or false. When populations do not exceed their environment carrying capacity biology communities are stable?
Answer:
True
Explanation:
n resistance is each of resistance R is first connected in series and then in parallel what is the ratio of series and parallel combination
Answer:
The ratio of the ratio of series and parallel combination is n²:1.
Explanation:
The equivalent resistance in case of series combination is given by :
[tex]R_s=R_1+R_2+.....+R_n=nR[/tex] ....(1)
The equivalent resistance in case of parallel combination is given by :
[tex]R_P=\dfrac{1}{R_1}+\dfrac{1}{R_2}+.....+\dfrac{1}{R_n}=\dfrac{R}{n}[/tex] ....(2)
Dividing equation (1) and (2) we get :
[tex]\dfrac{R_s}{R_P}=\dfrac{nR}{R/n}\\\\\dfrac{R_s}{R_P}=\dfrac{n^2}{1}\\\\R_s:R_P=n^2:1[/tex]
So, the ratio of the ratio of series and parallel combination is n²:1. Hence, this is the required solution.
n resistance is each of resistance R is first connected in series and then in parallel , the ratio of series and parallel combination will be [tex]n^{2}[/tex] : 1
In a series combination, the resistances are connected with end to end in contact, such that current flow is equal in all the resistances in the combination. Whereas in the parallel combination, resistances are connected in such a manner that they get an equal voltage across their ends.
Parallel combination. When two or more resistances are connected between the same two points, they are said to be connected in parallel combination. The reciprocal of the combined resistance of a number of resistances connected in parallel is equal to the sum of the reciprocals of all the individual resistances.
if n number of resistances are connected in series combination .
R (equivalent ) = R1 + R2 + R3 + R4 -------- + Rn
= R + R + R + R ---------------- + R
= n*R
if n number of resistances are connected in parallel combination .
1/ R (equivalent ) = 1/R1 + 1/R2 + 1/R3 ---------------- 1/Rn
= 1/R + 1/R + 1/R + --------------------- 1/R
= n/R
R (equivalent ) = R/n
Ration = series combination / parallel combination
= n*R / (R/n) = [tex]n^{2}[/tex] /1
= [tex]n^{2}[/tex] : 1
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someone pls help me this is due today!!!
Answer:
a. 6 A
b. 3 V
Explanation:
a. By using Kirchoff's Junction Rule, which states that the current flowing into a junction must equal the current flowing out of it. As you can see in the first 3-way split, the current splits into 3A, 2A, and 1A. This means that when the 3 wires rejoin, the current must have a magnitude equal to the total of the current flowing in all 3 branches, which would equate to 3+2+1 = 6 A.
b. Voltage differences across branches of a parallel circuit are identical. This means that we can treat the 3 resistors as one, and say that the voltage drop across that whole area is 3 V. Since that is the only voltage drop in the circuit, the battery's voltage drop must also be 3 V to equate to it. This is explained by Kirchoff's Loop Rule.
Prove that the acceleration due to gravity is independent to
the mass of the falling body
Answer:
The force of gravity on an object increases with its mass; thus, the acceleration of gravity is constant.
Explanation:
one can prove this by plugging in values to Newton's 2nd law equation
F = ma, or by using the formula to calculate the force of gravity.
Force of Gravity = GMm/r^2
with G being the gravitational constant, M the mass of the earth, m the mass of the falling body, and r the distance from the earth's center.
Force of Gravity can be written as mg, with g being the acceleration due to gravity.
As we can see, m cancels on both sides, leaving
g = GM/r^2
Generally in physics problems, r will be treated as constant to achieve
g = 9.8m/s^2
How did Einstein’s and Newton’s theories differ in terms of explaining the cause of gravity?
Newton's law of universal gravitation doesn't say anything about the cause of gravity.
Einstein's theory of relativity does.
Objects A and B have equal amounts volumes and are both traveling at 25 miles per hour. Object A is much denser than Object B. Which object has a greater amount of force and why
Answer:
Object A
Explanation:
Mass of an object= Volume × denstiy
Object having higher density will have greater mass
Next,
According to second law of Newton
Force= mass× acceleration
Force= mass× change is velocity/ time
For an equal amount of time, if change in velocity is equal then object with higher mass will have higher force. Hence, greater density, greater is mass and larger is the force.
