Answer:
1½ hours
Explanation:
Let the amount of time she drove at 85.5 km/hr be t, then
The distance that she rode would be 85.5 * t
This is means Emily has traveled the same distance at 68.8 km/hr without any stoppage whatsoever. Thus, we can create an equation as such
85.5 * t = 68.8 (t + 22/60), the 22/60 being, converting 22 minutes into hours. We proceed further as
85.5t = 68.8t + 1513.6/60, multiplying all sides by 60, we have
5130t = 4128t + 1513.6, now we collect like terms
5130t - 4128t = 1513.6
1002t = 1513.6
t = 1513.6/1002
t = 1.51 hrs, or in minutes, 1.51 * 60
t = 90.63 minutes. 1 hour and 36 minutes
So the total time the trip took, 22 minutes in addition, or say, 1 hour 58 minutes.
Michael threw a football and it traveled for 8 seconds at a velocity of 3 meters per second. How far did the football travel?
An airplane traveled 2,400 meters in 3 seconds. How fast was the plane going?
Answer:
800 miles per hour
Explanation:
There are two ways that an object can get in motion. What are they?
Answer:
pull or pushExplanation:
According to Newton's first law of motion "An object will continue to stay or remain at rest or continue to be in constant motion "unless acted upon by an external force"
F= ma
Basically a force is a pull or a push
so in other words the two ways by which an object can get in motion is by
1. A pull force
2. A push force
An object is thrown upward at an angle θ above the ground, eventually returning to earth. (a) Is there any place along the trajectory where the velocity and acceleration are perpendicular? If so, where? at the initial position of motion at the highest point in the trajectory at the final position of motion velocity and acceleration are never perpendicular
Answer:
Yes, at the highest point in the trajectory velocity and acceleration are perpendicular.
Explanation:
Let [tex]x-[/tex]axis be the ground and [tex]y-[/tex]axis is the height above the ground. Let the initial velocity of the object is [tex]u[/tex] having angle [tex]\theta[/tex] with respect to ground and the acceleration due to gravity , [tex]g[/tex], is acting in vertically downward direction as shown in figure.
As gravitational force is acting in vertical direction, so, it will not change the horizontal velocity of the object. So, at any instant throughout the projectile motion the [tex]x-[/tex]component of the initial velocity will remailns constant, i.e. [tex]u_x=u \cos \theta[/tex].
While, due gravitational force, [tex]y-[/tex]component of the initial velocity will change. Initially, [tex]u_y=u \sin \theta[/tex] is in vertically upward direction and gravitational force is actiongn vertically downward direction, so, at first [tex]u_y[/tex] will decrease untill it reaches the highest point of the trajectory as shown. At the highest point the vertical component of the velocity [tex]u_y=0[/tex], so, there is only horizontal component of the velocity. i.e [tex]u_x= u \cos\theta[/tex] .
Now, the resultant velocity of the object at the highest point is [tex]u \cos \theta[/tex] which is in the horizontal direction while the acceleration , [tex]g[/tex] , (due to gravily) is actiog in vertically downward direction.
Hence, at the highest point in the trajectory velocity and acceleration are perpendicular.
Somewhere at the greatest point of the trajectory, vector quantities become perpendicular. Considering gravity constantly pushes downward, a projectile's acceleration would always be downward.Furthermore, because the vertical velocity of something like a projectile approaches zero at the height of its trajectory, the first and only portion of the velocity which thus might not be zero seems to be the horizontal factor.
Thus the response above is appropriate.
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When air sinks, it:_________
(a) compresses and warms.
(b) reaches its equilibrium level and then begins to sink.
(c) expands and cools.
(d) forms into clouds.
Answer:
a) compresses and warms.
Explanation:
When air sinks, it falls down and compresses the air close to the surface of the ground, which raises the temperature of the air (since compression results in a rise in temperature). Also, as the air sinks, it prevent the already warm air close to the surface from rising, further increasing its own temperature, warming it up.
using keplers 3rd law, determine the distance between the earth and the sun
Answer:
93.615 million or more
Explanation:
The Sun is about 93 million miles from Earth to calculate the distance to a star, astronomers observe it from different places along Earth's orbit around the Sun.
You are given a vector in the XY plane that has a magnitude of 89.0 units and a y component of -70.0 units.
The pacefic ocean has a surface area of about 166 241 700km^2 and an average depth of 3940 m. Estimate the volume of the Pacific ocean in cubic centimetres
Answer:
[tex] \lim_{(x,y) \to \(0,0)} \frac{2x {y}^{2} }{ {x}^{2} {y}^{2} } [/tex]
Explanation:
[tex]\lim_{(x,y) \to \(0,0)}[/tex]
if 1 foot is 30.28 centimeters.how many cm is 130 feet
Answer:3,936.4
Explanation:
If 1 foot is 30.28 centimeters multiply 30.28 by 130
9. Which unit goes with time
kg
K
s
mm
A cement block accidentally falls from rest from the ledge of a 51.1-m-high building. When the block is 13.4 m above the ground, a man, 1.70 m tall, looks up and notices that the block is directly above him. How much time, at most, does the man have to get out of the way?
Answer:
The man has, at most, 0.4 secs to get out of the way
Explanation:
First, we will determine, the time the block takes to reach height 13.4 m above the ground.
Also, we will determine the time it will take to reach the man, if he does not notice it.
Then, the difference in the two times will be the time the man has to get out of the way.
From the formula
[tex]h =ut - \frac{1}{2}gt^{2}[/tex]
Where [tex]h[/tex] is height
[tex]u[/tex] is the initial velocity
[tex]t[/tex] is time
and [tex]g[/tex] is acceleration due to gravity ( Take [tex]g =[/tex] 9.8 m/s²)
Let the time the block takes to reach height 13.4 m be [tex]t_{1}[/tex]
The cement block falls from a 51.1 m high building, then by the time it reaches a height 13.4 m above the ground, the displacement is
13.4 m - 51.1 m = - 37.7 m
The is the height the block has fallen from by the time it gets to a height 13.4 m above the ground
Then,
[tex]h =ut - \frac{1}{2}gt^{2}[/tex]
[tex]-37.7 = (0)(t_{1}) - \frac{1}{2}(9.8)t_{1}^{2}[/tex]
(NOTE: [tex]u[/tex] = 0 m/s because the cement block falls from rest)
[tex]37.7 = 4.9t_{1}^{2}[/tex]
[tex]t_{1}^{2}= \frac{37.7}{4.9}[/tex]
[tex]t_{1}= \sqrt{7.69} \\[/tex]
[tex]t_{1}= 2.77 secs[/tex]
Hence, It takes the block 2.77 secs to reach height 13.4 m
Also,
Let the time it will take to reach the man be [tex]t_{2}[/tex]
The man is 1.70 m tall, hence, to reach the man, the cement block would have reached a height ( 1.70 m - 51.1 m) = - 49.4 m
Then,
[tex]h =ut - \frac{1}{2}gt^{2}[/tex]
[tex]-49.4 = (0)(t_{2}) - \frac{1}{2}(9.8)t_{2}^{2}[/tex]
[tex]49.4 = 4.9t_{2}^{2}[/tex]
[tex]t_{2}^{2} = \frac{49.4}{4.9}[/tex]
[tex]t_{2}= \sqrt{10.08}[/tex]
[tex]t_{2}= 3.17 secs[/tex]
Hence, it will take 3.17 secs to reach the man
Now, for the time the man has to get out of the way, that is
[tex]t_{2} - t_{1}[/tex] = 3.17 secs - 2.77 secs
= 0.4 secs
Hence, the man has, at most, 0.4 secs to get out of the way
Which of the following quantities represent mass?
a. 12.0 lbs.
b. 0.34 g.
c. 120 kg.
d. 1600 kN.
e. 0.34 m.
f. 411 cm.
g. 899 MN.
Answer:
Explanation:
a ) 12.0 lbs - mass
b ) .34 g - mass
c ) 120 kg - mass
As lbs , g and kg are units of mass , these things represent mass . lbs is FPS unit of mass and kg is SI unit . g is CGS unit of force .
d ) 1600 kN It represents force because kN or kilonewton is unit of force .
e ) it represents , length or distance because m or metre is unit of length .
f ) 411 cm It represents length or distance because cm is smaller unit of length
g ) 899 MN or million newton . Like d ) It also represents force . Million newton is higher unit of force .
What is a main difference between a mixture and a pure substance?
O A mixture is only a liquid, but a pure substance can be in any state.
A mixture looks the same throughout, but a pure substance does not.
A mixture can vary in composition, but a pure substance has a set composition.
A mixture can be made up of a single compound, but a pure substance cannot.
оо
Answer:
C- A mixture can vary in composition, but a pure substance has a set composition
Explanation:
The main difference between a mixture and a pure substance is: A mixture can vary in composition, but a pure substance has a set composition ( option c )
MixtureA mixture is a substance which contains two or more constituents which can easily be separated by a physical means. It consists of two or more different substances, not chemically joined together.
SubstanceA pure substance consists only of one element or one compound.
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Which refers to the ratio of output work to input work of a machine expressed as a percent?
total work
wattage
efficiency
power
Answer:
Efficiency Or C. on e2020
The ratio of output work to input work of a machine expressed as a percent refers to efficiency of the machine.
What is efficiency of machine?How well a machine converts its input energy into useable output energy, or work, is referred to as its efficiency. It is the portion or percentage of the output divided by the input, and it plays a significant role in a machine's utility.
It denotes the degree of performance that requires the fewest inputs to provide the greatest amount of output in more mathematical or scientific words. It frequently particularly refers to the ability of a particular application of effort to deliver a particular output with the least amount of waste, expense, or superfluous work. Efficiency covers a wide range of inputs and outputs across numerous disciplines and sectors.
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position (m)
80!
В
с
60
40
20
A
- 20
-40
10
20
30
40
50
time (sec)
Answer:
hola bb como estas dime bb en que te ayudo
Explanation:
a ball rolling down a hill was displaced 21.9 m while using uniformly accelerating from rest, If the final velocity was 7.14 m/s, what was the rate of acceleration?
Answer:
a = 1.16 m/s²
Explanation:
In order to find the rate of acceleration of the ball, we will use third equation of motion, as follows:
2as = Vf² - Vi²
where,
a = rate of acceleration = ?
s = distance covered by the ball = 21.9 m
Vf = Final Velocity of the ball = 7.14 m/s
Vi = Initial Velocity of the ball = 0 m/s (Since, the ball started from rest)
Therefore,
2(a)(21.9 m) = (7.14 m/s)² - (0 m/s)²
a = (50.97 m²/s²)/(43.8 m)
a = 1.16 m/s²
if a car is traveling with a velocity of 20 m/s, how long will it take to reach 4000m
a golf ball is launched straight up with an initial velocity of 15.68m/s. Calculate the balls displacement and velocity every 0.4 sec into the ball's flight. How long will it take the ball in the air?
Explanation:
Given:
v₀ = 15.68 m/s
a = -9.8 m/s²
t = 0.4n s, n = 0, 1, 2, etc.
Find: Δy and v
To find displacement, use the equation:
Δy = v₀ t + ½ at²
To find velocity, use the equation:
v = at + v₀
[tex]\left\begin{array}{ccc}t&y&v\\0&0&15.68\\0.4&5.49&11.76\\0.8&9.41&7.84\\1.2&11.76&3.92\\1.6&12.54&0\\2.0&11.76&-3.92\\2.4&9.41&-7.84\\2.8&5.49&-11.76\\3.2&0&-15.68\end{array}\right[/tex]
The ball lands after 3.2 seconds.
Answer:
calculated velocities:
(t,v(t))
(0.4,11.756)
(0.8,7.832)
(1.2,3.908)
(1.6,-0.016)
calculated displacements:
[tex](t,\Delta x)[/tex]
(0.4, 5.487)
(0.8,9.4048)
(1.2, 11.7528)
(1.6, 12.5312)
the ball spends 3.2 seconds in the air
Explanation:
Assuming the ball is launched on earth with standard gravity and that the effects of drag is neglected.
assume that 'up' is positive direciton since that is direction of travel
'down' is negative direction
formula for velocity is [tex]v(t)=v_0+at[/tex]
where [tex]v(t)[/tex] is the velocity at time [tex]t[/tex]
[tex]v_0[/tex] is the initial velocity at time [tex]t=0[/tex]
[tex]a[/tex] is the acceleration in the direction of the velocity
velocity is in m/s and accelration is in m/s^2 and t is in seconds
for displacement: [tex]\Delta x=v_0 t+\frac{1}{2}at^2[/tex]
Known stuffs:
in our case, we know we are on earth so, [tex]a=-9.81[/tex]m/s^2. the negative sign indicates that the direction is oposite the velocity since the ball travels up but gravity pulls down
the initial velocity is given as [tex]v_0=15.68[/tex]m/s
therefore, our equation for velocity is
[tex]v(x)=15.68-9.81t[/tex]
now we just need to plot it every 0.4 seconds
this is easy subsituteion. here's the first:
[tex]v(0.4)=15.68-9.81(0.4)=11.756[/tex]m/s
if we keep plotting this, we get the following table
(t,v(t))
(0.4,11.756)
(0.8,7.832)
(1.2,3.908)
(1.6,-0.016) the velocity is negative meaning that the ball is now going 'down' and therefor the ball has just passed the peak of it's upward travel
so since it took about 1.6 seconds to get here, it will spend about twice this time in the air or about 3.2 seconds
to get an exact answer, solve for the time when velocity is 0, ie when the ball has reached its peak and stopped moving
set [tex]v(t)=0[/tex] and solve for t
[tex]0=15.68-9.81t\rightarrow 15.68=9.81t\rightarrow t=1.598s[/tex]
so it takes 1.598 seconds to get to peak, therefore it spends twice this time in the air or 3.197 seconds in the air. it's close enough to 3.2 seconds
the ball spends 3.2 seconds in the air
displacement:
[tex]\Delta x=v_0t+\frac{1}{2}at^2[/tex]
[tex]\Delta x=15.68t+\frac{1}{2}(-9.81)t^2[/tex]
some values are
[tex](t,\Delta x)[/tex]
(0.4, 5.487)
(0.8,9.4048)
(1.2, 11.7528)
(1.6, 12.5312)
A car traveling with an initial velocity of 10 m/s accelerates at a constant rate of 2.2 m/s^2 for 2 seconds. What distance does the car travel during this process
2.5 better than the first one more game to go hard but I 46 the bucks
Answer:
hsiahdjjsdhishshdakyeacs4y9yssig
Explanation:
ntesgs7thsjv6wlubx4euc
Could someone tell me if this is right or give me the answers so i can re write them! That would be so helpful:)
Answer:
Those are all right
Explanation:
Answer:
They are right! Nice job!
Explanation:
Saturn is 890,700,000 miles from the Sun. What is this distance in scientific notation? The ratio of miles to meters is 1 mile equals 1.61 x 103 meters. What is this distance in meters? If the speed of light is 3.0 x 108 meters/second, how long does it take for light from the Sun to reach Saturn? Hint: Use the distance in meters to calculate.
Answer:
13 hours, 16 minutes, 41 seconds
Explanation:
Distance of Saturn from the Sun
= 890,700,000 miles
[tex] = 8.907\times 10^8 \: miles\\
= 8.907\times 10^8 \times 1.61 \times 10^3 \:meters\\
= 14.34027\times 10^{11}\: m\\
= 1. 434027\times 10^{12}\: m\\\\
\because Time = \frac{Distance}{Speed} \\
\therefore Time = \frac{1.434027\times 10^{12}}{3\times 10^8}\\
\therefore Time = 4.78009 \times 10^{12-8}\\
\therefore Time = 4.78009 \times 10^{4} \:seconds \\
\therefore Time = 47800.9 \:seconds\\
\therefore Time = 47801 \:seconds\\
\therefore Time = 13h\: 16m\: 41s\\[/tex]
Saturn is 890,700,000 miles from the Sun. This distance in the scientific notation would be 1.434×10¹² metes.
If the speed of light is 3.0 x 108 meters/second, then it would take 4780 seconds for light from the Sun to reach Saturn.
What is Velocity?The total displacement covered by any object per unit of time is known as velocity. It depends on the magnitude as well as the direction of the moving object. The unit of velocity is meter/second. It can also be represented by the infinitesimal rate of change of displacement with respect to time. The generally considered unit for velocity is a meter per second.
As given in the problem Saturn is 890,700,000 miles from the Sun
1 mile = 1.61 x 10³ meters
890,700,000 miles = 890,700,000×1.61×10³ meters
=1.434×10¹² metes
As given If the speed of light is 3.0 x 10⁸ meters/second
Time = distance /speed
= 1.434×10¹² metes / 3.0 x 10⁸ meters/second
= 4780 seconds
Thus, the distance in the scientific notation would be 1.434×10¹² metes and it would take 4780 seconds for light from the Sun to reach Saturn.
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What three forms of energy are represented when a match is lit?
Answer:
Three forms of energy when a match is being lit are potential, kinetic and thermal.
hope this helps! :)
Explanation:
Answer:
Potential Energy
Kinetic Energy
Thermal Energy
Explanation:
What is the key difference between acentralized electrical distribution grid versus a distributed electrical distribution grid? I am using the textbook provided but I can not find an answer
The electricity generated by centralized generation is distributed through the electric power grid to multiple end-users. Centralized generation facilities include fossil-fuel-fired power plants, nuclear power plants, hydroelectric dams, wind farms, and more.
After a group of researchers conducts a new experiment that has never been conducted before, what is the best way for other scientists to make sure that the data is real?
Answer:
I think it would be interviewing the researchers I'm unsure though
Answer:
Probably C) Conducting the experiment again
Explanation:
Option A is wrong because there is a chance that the group of researchers made a mistake or got the wrong data. So when interviewing the researchers, there is a chance of them giving the wrong data, especially since the experiment has never been conducted before.
Option B is wrong because the experiment the researchers where doing was new and has never been conducted before. Therefore there is no older research done on that topic.
Option C is correct because when conducted the experiment again, they can compare their results with the group of researchers. Checking if the data is correct.
Option D is wrong because the group of researchers might have made a mistake when writing down the procedure, leading to false data.
electricity is one kind of
Answer:
I think electricity is one kind of energy
The voltage across a 8.5-F capacitor is 2te–3t V. Find the current and the power.
Answer:
Explanation:
Given the capacitance of a capacitor = 8.5F
Voltage across the capacitor = 2te^-3tV
The current across a capacitor is expresses as shown;
I = Cdv/dt
Given V = 2te^-3tV
dv/dt = 2t(-3e^-3t) + 2(e^-3t)
dv/dt = -6te^-3t + 2e^-3t
Factor out the common term
dv/dt = -2e^-3t{3t-1}
If C = 8.5F
I = 8.5 × -2e^-3t{3t-1}
I = -17.0e^-3t{3t-1} A
Power is the product of current and voltage.
P = IV
Given I = -17.0e^-3t{3t-1} A
V = 2te^-3t V
Power = -17.0e^-3t{3t-1} × 2te^-3t
Power = (17e^-3t - 51te^-3t) × 2te^-3t
Power = 34te^{-3t-3t} - 102t²e^{-3t-3t}
Power = 34te^-6t - 102t²e^-6t
Power = 34te^-6t{1-3t} Watts
A web page designer creates an animation in which a dot on a computer screen has a position of r⃗ =[ 4.50 cm +( 2.90 cm/s2 )t2]i^+( 4.70 cm/s )tj^ . Part A Find the average velocity of the dot between t=0 and t=2.0s. Give your answer as a pair of components separated by a comma. For example, if you think the x component is 3 and the y component is 4, then you should enter 3,4.
Answer:
V = (5.8cm/s)i, (4.7cm/s)j
Explanation:
Given :
r⃗ =[ 4.50 cm +( 2.90 cm/s2 )t2]i^+( 4.70 cm/s )tj^
To obtain the average velocity (V)
V = (r2 - r1) / (t2 - t1)
To obtain r1 and r2, substitute t1 = 0 and t2 = 2 respectively in the equation above
r1 = [ 4.50 cm +( 2.90 cm/s2 ) 0]i^+( 4.70 cm/s )0 j
r1 = 4.50 cm + 0 + 0 = (4.50cm)i + 0j
r2 = [ 4.50 cm +( 2.90 cm/s2 )2²]i^+( 4.70 cm/s )2 j
r2 = 4.50cm + (2.90 × 4)i + (4.70 × 2)j
r2 = (16.1cm)i + (9.4cm)j
V = [(16.1 - 4.50)i - (9.4 - 0)j] / 2 - 0
V = 11.6i / 2 ; 9.4j / 2
V = (5.8cm/s)i, (4.7cm/s)j
What is applied force?
Answer:
An applied force is a force that is applied to an object by a person or another object. If a person is pushing a desk across the room, then there is an applied force acting upon the object.
Explanation:
Julie, a third-grade student, believes that the moon disappears on certain days every month. Explain why the following information is or is not scientific evidence which can be used to evaluate Julie’s hypothesis.
_____ electrons are the most important electrons to an atom .
Answer:
stable is the answer
Explanation:
stable electrons
