Answer:
Option B. 28 N
Explanation:
From the question given above, the following data were obtained:
Coefficient of static friction (μ) = 0.35
Normal force (N) = 80 N
Frictional force (F) =?
The coefficient of static friction, frictional force and the normal force are related according to the following equation:
Coefficient of friction = frictional force / normal force
μ = F/N
With the above formula, we can obtain the frictional force as follow:
Coefficient of static friction (μ) = 0.35
Normal force (N) = 80 N
Frictional force (F) =?
μ = F/N
0.35 = F / 80
Cross multiply
F = 0.35 × 80
F = 28 N
Thus the frictional force is 28 N
Answer:
Option B. 28 N
Explanation:
PLEASE HELP!! URGENT!!
Which of the following is not a true statement?
v=at
O art
Answer:
t = Δa / v
Explanation:
To know which option is not true, we shall fine a relationship between acceleration (a), velocity (v), time (t) and radius (r). This is illustrated below:
Acceleration can simply be defined as the rate of change of velocity with time. Mathematically, it is expressed as shown below:
Acceleration = change in velocity / time
a = Δv / t ..... (1)
But
Δv = v₂ – v₁
Substitute the value of Δv into equation (1)
a = Δv / t
a = v₂ – v₁ / t ....... (2)
From equation (1), make Δv the subject of the equation.
a = Δv / t
Cross multiply
Δv = at .... (3)
From equation (1), make t the subject of the equation.
a = Δv / t
Cross multiply
at = Δv
Divide both side by a
t = Δv /a ...... (4)
From circular motion, centripetal's force is given by:
F = mv²/r
F = ma꜀
Therefore,
ma꜀ = mv²/r
Cancel out m
a꜀ = v²/r
SUMMARY:
a = Δv / t
a = v₂ – v₁ / t
Δv = at
t = Δv /a
a꜀ = v²/r
Considering the options given in question above, t = Δa / v is not a true statement.
Answer:
Option 4
Explanation:
Which type of electromagnetic wave has the least energy?
O A. Ultraviolet
O B. Infrared
O C. Microwaves
O D. Radio
Help!
Answer:
The answer is radio waves
find the potential energy of an aircraft weighing 10000 bs at 5000 ft true altitude and 125 kts true air speed
Answer:
[tex]U=5*10^7ft.Ib[/tex]
Explanation:
From the question we are told that
Weight [tex]W= 10000bs[/tex]
Altitude [tex]H=5000ft[/tex]
Speed [tex]V=125kts\\1kts=0.514m/s\\V=125*0.514=>64.25m/s[/tex]
Generally the equation for Potential energy ids mathematically given as
[tex]Potential\ Energy\ U=mgh[/tex]
[tex]U=Wh[/tex]
[tex]U=10000*5000[/tex]
[tex]U=5*10^7ft.Ib[/tex]
A 12-kg hammer strikes a nail at a velocity of and comes to rest in a time interval of 8.0 ms. (a) What is the impulse given to the nail
Answer:
Impulse = 0.9408Ns
Explanation:
Impulse is the product of force and time
Impulse = Ft
Given
Force F = mg
F = 12(9.8)
F = 117.6N
Time = 8 * 10^-3 = 0.008s
Get the impulse
Impulse = 117.6*0.008
Impulse = 0.9408Ns
When a high voltage is applied to a low-pressure gas causing it to glow, it will generate which type of spectrum
Answer:
Line emission.
Explanation:
According to Isaac Newton, he postulated that light consists of little (tiny) particles which typically travels in a straight line and from his experimental investigation he observed that white light comprises of a mixture of colors.
Sir Newton observed that, when light shines on a piece of metal, the metal releases electrons because the energy of the tiny light particles are greater than the binding energy of the electrons residing in the metal. This theory is known as the particle model of light.
A line emission would appear in a spectrum when specific wavelength is being emitted by the source of light.
When a high voltage is applied to a low-pressure gas causing it to glow, it will generate line emission.
For example, if a sample of hydrogen gas at low-pressure undergoes or experiences a high voltage electrical discharge, the isolated hydrogen gas would generate a red light (line emission).
What is the density of a cube that has a mass of 3.75 g and a volume of 3 mL?
Answer:
[tex]\displaystyle \rho=1.25\ g/ml[/tex]
Explanation:
Density
The density of a substance is the mass per unit volume. The density varies with temperature and pressure.
The formula to calculate the density of a substance of mass (m) and volume (V) is:
[tex]\displaystyle \rho=\frac{m}{V}[/tex]
The cube has a mass of m=3.75 g and a volume of V=3 ml, thus the density is:
[tex]\displaystyle \rho=\frac{3.75\ g}{3\ ml}[/tex]
[tex]\boxed{\displaystyle \rho=1.25\ g/ml}[/tex]
Since 1 kg=1000 mg and 1 lt = 1000 ml, the density has the same value but with different units:
[tex]\displaystyle \rho=1.25\ kg/l[/tex]
The graph below shows the force required to stretch a spring various distances. Review the graph below.
What is the best approximate value for the elastic potential energy (EPE) of the spring elongated by 3.0 meters?
Explanation:
Elastic string constant (k)
= Slope of the graph F/x
= 15.0N/10.0m = 1.50N/m
Hence,
EPE = 0.5kx² = 0.5(1.50N/m)(3.0m)² = 6.75J.
Answer:
6.8
Explanation:
Who pays for Government workers that work on alcohol impaired driving cases?
Answer: Taxpayers
Explanation:
Taking alcohol before driving or while driving is dangerous and has resulted in lots of accidents and deaths. Alcohol tampers with the normal functioning of the brain, and also impairs ones reasoning.
Alcohol impaired driving cases handled by government officials are paid for by the taxpayers. A tax is the levy that the people in the country pays. Those funds are used in handling different government objectives and this is one of such ways.
True or false: There is only one possible choice of system which could be correct when doing problems using work and energy.
Answer:
the relationship is scalar, it is independent of the specific reference system
The statement is false
Explanation:
When the concepts of work and energy are being used, a reference system must be defined to perform the calculations,
in the case of work it is defined by the relation
W = F. d
where the point represents the scalar product, therefore the work is a scalar magnitude, it has only modulus for which any reference system is selected since the result is independent of the direction of the force, only the projection of the force depends in the given direction.
For the part of the energy it therefore has two main forms, kinetic energy and potential energy.
For kinetic energy the expression is
K = ½ m v²
therefore, the energizes only depends on the speed module and any reference system, since it will be selected
for gravitational and elastic power energy. It does not depend on the specific value at the point but on the difference with respect to an arbitrarily defined zero, therefore, as the difference is constant, it is independent of the reference system used.
In conclusion, since the relationship is scalar, it is independent of the specific reference system, so we can select several reference systems
a bug is flying with a velocity of 10m/s into a wind at 3m/s what is the resultant velocity of the bug?
Nepal has high potential for producing hydroelectricity however it is difficult too give one reason of each
Answer:
due to the land structure of Nepal
(KInda need some help here. fast perferable) What is a controlled experiment? A. An experiment with one dependent variable and one experimental variable B. An experiment with only experimental variables C. An experiment with no controlled variables D. An experiment with no variables
Answer: A controlled experiment is a scientific test done under controlled conditions, meaning that just one (or a few) factors are changed at a time, while all others are kept constant. In some cases, there is no good way to test a hypothesis using a controlled experiment I hope this helps you
Explanation:
A spring is attached to the ceiling, and when a mass is suspended from the spring at rest, it stretches by 50 cm. If instead two identical copies of the same spring are attached to the mass and the ceiling, the springs will stretch by:
Answer:
25 cm
Explanation:
Given that :
Displacement, x = 50 cm
In a spring, the force is given thus ;
F = kx ; where, F = Force, k = spring constant
Hence,
F = 50k - - - (1)
If two identical springs are attached to the mass ;
Fnet = F1 + F2
Fnet = F = kx' + kx'
x' = Displacement
Spring constant k and x' will be the same in the two springs ;
Hence,
F = 2kx' - - - (2)
Equating (1) and (2)
F = F
50k = 2kx'
50 = 2x'
x' = 50 / 2
x' = 25
Hence, the spring will stretch by 25cm
Answer:
25m
Explanation:
5.An ice skater pushes against a wall with a force of 59 N. Ignoring friction, if the ice skater has
a total mass of 79 kg, what is the magnitude of his acceleration?
(A) 0.75 m/s2
(B) 1.3 m/s2
(C) 21 m/s2
Answer:
Answer: (A) 0.75 m/s^2
Explanation:
The Second Newton's law states that an object acquires acceleration when an external unbalanced net force is applied to it.
That acceleration is proportional to the net force and inversely proportional to the mass of the object.
It can be expressed with the formula:
[tex]\displaystyle a=\frac{F_n}{m}[/tex]
Where
Fn = Net force
m = mass
The ice skater pushes against a wall with a force of 59 N. The wall returns the force and the skater now has a net force of Fn=59 N that makes him accelerate. Being m=79 kg the mass of the skater, the acceleration is:
[tex]\displaystyle a=\frac{59}{79}[/tex]
[tex]a = 0.75\ m/s^2[/tex]
Answer: (A) 0.75 m/s^2
What is the target heart rate for a 24 year old?
Answer:
196
Explanation:
subtract 24 from 220 to get your answer.
Answer:
100 beats for minute
Explanation:
Adults ( age 18 and over) 60 - 100 beats per minute
A wave is traveling at a speed of 15 m/s and it's wavelength is 5 m. Calculate the waves frequency
Answer:
The frequency of this wave is [tex]3\; \rm Hz[/tex].
Explanation:
The frequency [tex]f[/tex] of a wave is the number of wavelengths that this wave covers in unit time (typically a second.)
The wave in this question travels at [tex]v = 15\; \rm m \cdot s^{-1}[/tex]. In other words, this wave covers [tex]15\; \rm m[/tex] in unit time (a second.) How many wavelengths [tex]\lambda[/tex] would that [tex]15\; \rm m\;[/tex] correspond to?
The question states that the wavelength of this wave is [tex]\lambda = 5\; \rm m[/tex]. Therefore, there would be [tex]15 / 5 = 3[/tex] wavelengths in the [tex]15\; \rm m[/tex] span that this wave covered in the unit time of one second ([tex]1\; \rm s[/tex].) Hence, the frequency of this wave would be [tex]3\; \rm s^{-1}[/tex] (three per second,) which is equivalent to [tex]3\; \rm Hz[/tex] (three Hertzs.)
In general, the frequency [tex]f[/tex] of a wave with speed [tex]v[/tex] and wavelength [tex]\lambda[/tex] would be:
[tex]\displaystyle f = \frac{v}{\lambda}[/tex].
For the wave in this question:
[tex]\begin{aligned}f &= \frac{v}{\lambda} \\ &= \frac{15\; \rm m \cdot s^{-1}}{3\; \rm s} = 3\; \rm s^{-1} = 3\; \rm Hz\end{aligned}[/tex].
an object on a number like moved from x = 12 m to x = 124 m and moved back to x = 98 m. the time interval for all the motion was 10 s. what was the average velocity of the object?
Complete Question:
an object on a number line moved from x = 12 m to x = 124 m and moved back to x = 98 m. the time interval for all the motion was 10 s. what was the average velocity of the object?
Answer:
v = 8.6 m/s
Explanation:
By definition, the average velocity, is just the rate of change of the position (denoted by the x-coordinate in this case) with respect to time, as follows:[tex]v_{avg} =\frac{x_{f} -x_{o}}{t_{f} - t_{o} } (1)[/tex]
This means that the average velocity depends only on the final and initial positions, independent from the intermediate points between them.As we can choose freely our origin in time, we choose the initial time to be zero.At that time, the x-coordinate is x=12 m, so x₀ = 12 m.When t= 10.0 s, x is 98 m, so xf = 98 m.Replacing in (1) we get:[tex]v_{avg} =\frac{x_{f} -x_{o}}{t_{f} - t_{o} } =\frac{98 m -12 m}{10.0 s - 0 s } = \frac{86m}{10.0s} = 8.6 m/s (2)[/tex]
The rate of conduction heat transfer through a plane wall of dimensions , and , thermal conductivity , and temperatures and on the faces can be determined as
Answer:
Answer is explained in the explanation section below.
Explanation:
It can be determined by the use of Fourier's law of heat conduction.
Fourier's Law of Heat Conduction: States that, the rate of heat transfer is directly proportional to the temperature change from higher temperature to lower temperature. And it is directly proportional to the area perpendicular to the direction of the heat flow.
Through this statement, we can write the equation of the Fourier's law:
Q = Rate of Heat transfer.
A = Area
dT = Change in Temperature from Higher to Lower = T1 - T2, where T1 is assumed to be higher temperature.
dx = thickness of the wall, through which heat is transferring.
So,
Q is directly proportional to Area perpendicular to the direction of the heat flow.
So, we can write:
Q [tex]\alpha[/tex] A
And
Q is directly proportional to temperature change.
So, we can write
Q [tex]\alpha[/tex] dT/dx
So, in order to remove the proportionality sign, we need to introduce a constant, which is ( -K) here, Thermal conductivity material of the plane wall.
So,
Q = - K.A . dT/dx
or
Q = - K . (H.W) . (T1-T2)/L
where, H = height of the wall
W = width of the wall
L = length of the wall.
So, by using the above equation, we can definitely determine the rate of heat transfer through a plane -wall.
Note: for your ease, I have drawn a schematic of the plane-wall and attached in the attachment.
Starting from rest, a car takes 2.4 s to travel the first 15 m. Assuming a constant acceleration, how long will it take the car to travel the next 15 m?
A) 1.0s
B) 3.6s
Answer:
letter B.
Explanation:
Answer: A
0.1
Explanation: I did this
3.) A family travels by car cross country 6,200 km in 80 hours. In meters per 1 point
second, how fast did the family travel? (3600 seconds = 1 hour) (Show ALL
work!) *
Answer:
v = 21.52 m/s
Explanation:
Given that,
The distance covered by the car, d = 6200 km
Time taken by the car, t = 80 hours
We need to find the speed of the car. The speed of an object is given by total distance dividing total time.
[tex]v=\dfrac{6200\times 10^3\ m}{80\times 3600}\\\\v=21.52\ m/s[/tex]
So, the speed of the car is 21.52 m/s.
Weight _____. A) is related to mass, but not the same. B) changes as mass changes C) depends upon gravitational pull D) all of the above
Answer:
D) all of the above
Explanation:
All of the given choices are correct definition of what weight of a substance implies.
Weight is the vertical force on a body due to the gravitational attraction or pull.
Weight = mass x acceleration due to gravity
Mass of a body is directly proportional to its weight and so also is the gravity.
Mass is the amount of matter within a substance.
Weight is the force of gravity exerted by a body on another or a surface.
The reason why the weight of a body changes from place to place is mainly due to the gravitational pull
the reading on a mercury barometer at mombasa is 760mms.calculate the pressure at mombasa(density of mercury=1.36x10 power 4kg/m3
Answer:
The pressure at Mombasa is 101.396 KPascal.
Explanation:
Given: Reading on barometer = 760 mm
= 0.76 m
Density of mercury = 1.36 x [tex]10^{4}[/tex] kg/[tex]m^{3}[/tex]
In this case, the pressure can be expressed as:
P = σhg
Where: σ is the density of mercury, h is height of mercury in the barometer, and g is the acceleration due of gravity.
But, g = 9.81 m/[tex]s^{2}[/tex]
So that,
P = 1.36 x [tex]10^{4}[/tex] x 0.76 x 9.81
= 101396.16 Pascal
P = 101.395 KPascal
The pressure at Mombasa is 101.396 KPascal.
A ship's boiler steam comes out at 112 C and pushes through the system, exiting into the condenser,
which is kept at 20 C by circulating seawater. What is the ideal efficiency of the ship's boiler? Round to
the nearest thousandth.
O 0.643
O 0.523
O 0.703
O 0.239
Answer:
D: 0.239
Explanation:
Equation for ideal efficiency is;
η = 1 - (T_c/T_h)
We are told that;
steam comes out at 112° C. Thus, T_h = 112°C. Converting to Kelvin gives; T_h = 112 + 273 = 385 K
The one exiting into the condenser is kept at 20°C. Thus; T_c = 20 + 273 = 293 K
Thus;
η = 1 - (293/385)
η = 0.239
please do this . will mark as brainlest;)
Answer:
no, not all three contains iron
no, not all three also contain magnets
Explanation:
a has the magnet
b and c have pieces of iron
QUESTION 7
How much force is required to bring a car of mass 1,126 kg, initially traveling at 20.4 m/s, to rest in 7.4 s?
Answer:
The force required is 3,104 N
Explanation:
Force
According to the second Newton's law, the net force exerted by an external agent on an object of mass m is:
F = ma
Where a is the acceleration of the object.
On the other hand, the equations of the Kinematics describe the motion of the object by the equation:
[tex]v_f=v_o+at[/tex]
Where:
vf is the final speed
vo is the initial speed
a is the acceleration
t is the time
Solving for a:
[tex]\displaystyle a=\frac{v_f-v_o}{t}[/tex]
We are given the initial speed as vo=20.4 m/s, the final speed as vf=0 (at rest), and the time taken to stop the car as t=7.4 s. The acceleration is:
[tex]\displaystyle a=\frac{0-20.4}{7.4}[/tex]
[tex]a=-2.757\ m/s^2[/tex]
The acceleration is negative because the car is braking (losing speed). Now compute the force exerted on the car of mass m=1,126 kg:
[tex]F = 1,126\ kg * 2.757\ m/s^2[/tex]
F= 3,104 N
The force required is 3,104 N
Explain the meaning of the error
Answer:
a mistake
Explanation:
The frequency of a tuning fork can be found by the method shown. A long tube open at both ends is submerged in a beaker of water, and the vibrating tuning fork is placed near the top of the tube. The length L of the air column is adjusted by moving the tube vertically. The sound waves generated by the fork are reinforced when the length of the air column corresponds to one of the resonant frequencies of the tube. The smallest value for L for which a peak occurs in sound intensity is 5 cm.a) What is the frequency of the tuning fork? The speed of sound in air is 345 m/s. Answer in units of Hz.b) What is the value of L for the second resonant position? Answer in units of cm.c)What is the value of L for the third resonant position? Answer in units of cm.
Answer:
a. 3.45 kHz b. 5 cm c. 7.5 cm
Explanation:
a. What is the frequency of the tuning fork?
For a tube open at both ends, the frequency, f = nv/2L. The smallest frequency at the smallest length of air column, L = 5 cm = 0.05 m is the fundamental frequency and there, n = 1 and v = speed of sound in air = 345 m/s.
So, f = v/2L
So, f = 345 m/s/(2 × 0.05 m)
= 345 m/s ÷ 0.1 m
= 3450 Hz
= 3.45 kHz
b. What is the value of L for the second resonant position?
The second resonant frequency is f' = 2f
= 2 × 3450 Hz
= 6900 Hz
Since f = nv/2L and f' = second resonant frequency when n = 2.
So, f' = 2v/2L
f' = v/L
L = v/f'
= 345 m/s ÷ 6900 Hz
= 0.05 m
= 5 cm
c. What is the value of L for the third resonant position?
The third resonant frequency is f" = 3f
= 3 × 3450 Hz
= 10350 Hz
Since f = nv/2L and f" = third resonant frequency when n = 3.
So, f" = 3v/2L
2f' = 3v/L
L = 3v/2f'
= 3 × 345 m/s ÷ (2 × 6900 Hz)
= 1035 m/s ÷ 13800 Hz
= 0.075 m
= 7.5 cm
a)The frequency of the tuning fork will be 3.45 kHz.
b) The value of L for the second resonant position will be 5 cm.
c) The value of L for the third resonant position will be 7.5 cm.
What is frequency?Frequency is defined as the number of repetitions of a wave occurring waves in 1 second.
The tuning fork's frequency for a tube with both ends open is;
f = nv/2L
f = 345 m/s/(2 × 0.05 m)
f= (345 m/s) / (0.1 m)
f= 3450 Hz
f= 3.45 kHz
f' = 2f is the second resonant frequency.
f'= 2 × 3450 Hz
f'= 6900 Hz
f = nv/2L
For n=2,
f' = 2v/2L
f' = v/L
The value of L for the second resonant position;
L = v/f'
L= 345 m/s ÷ 6900 Hz
L= 0.05 m
L= 5 cm
f' = 3f is the third resonant frequency.
f' = 3 × 3450 Hz
f'= 10350 Hz
f = nv/2L
For, n = 3.
f' = 3v/2L
2f' = 3v/L
The value of L for the third resonant position;
L = 3v/2f'
L=( 3 × 345 m/s)/(2 × 6900 Hz)
L= 1035 m/s / 13800 Hz
L= 0.075 m
L= 7.5 cm
Hence,The frequency of the tuning fork,value of L for the second resonant position and value of L for the third resonant position will be 3.45 kHz. 5 cm and 7.5 cm respectively.
To learn more about the frequency refer to the link;
https://brainly.com/question/14926605
#SPJ5
15. If friction was completely removed from the track, what affect would this have on the roller coaster ride?
A. Without friction, the roller coaster ride would last forever!
B. The coaster would eventually stop because the coaster would still lose energy.
C. The coaster would use hills and flat sections to stop instead.
How much work is required to lift 40 N 1.5 M
Answer: 200 joules I think.
Explanation:
