Question

acceleration and velocity

Answer 1

A train travels at a velocity of +50 m/s. It takes 80 s to slow down to 5 m/s with constant acceleration. What was its acceleration?
A. -0.064 m/s2
B. -0.56 m/s2
C. -8.0 m/s2
D. -10.0 m/s2

On Earth a rock is dropped and falls 4.9 meters just before it hits the ground. How much time did the rock take to fall this distance?
A. 0.5 s
B. 1.0 s
C. 1.2 s
D. 2.45 s

A girl throws a tennis ball upward with an initial velocity of 4 m/s. What is the maximum displacement of the ball?
A. 0.2 m up
B. 0.4 m up
C. 0.8 m up
D. 1.6 m up


A car traveling at +30 m/s brakes to exit the highway with an average acceleration of -3 m/s2. About how long is it before the car slows to +5 m/s?
A. 5 s
B. 8 s
C. 10 s
D. 18 s


A child throws a penny straight down into a wishing well. The penny's initial speed is 2 m/s. If the penny takes 3 seconds to hit the water, how deep is the well?
A. 20 m down
B. 46 m down
C. 50 m down
D. 94 m down


A spaceship starting from a resting position accelerates at a constant rate of 9.8 meters per second per second. How far will the spaceship travel if its final speed is 1 percent the speed of light (300,000,000 m/s)?
A. 3.1 × 106 m
B. 2.94 × 108 m
C. 7.8 × 1010 m
D. 4.6 × 1013 m


A model rocket is shot straight upward with an initial velocity of 32 m/s. Its upward acceleration is a constant 6 m/s2. When the fuel is used up at a height of 75 m, what is its velocity?
A. 30 m/s up
B. 32 m/s up
C. 38 m/s up
D. 44 m/s up

A car starts from a resting position and accelerates at a constant rate of 6 meters per second per second. What is the car's speed after it has traveled 250 meters?
A. 41.7 m/s
B. 54.8 m/s
C. 127.3 m/s
D. 1500 m/s


If a bicyclist starts from a resting position and reaches a speed of 10 meters per second in 40 seconds, what was his acceleration during this time? Assume he accelerated in a constant way.
A. 0.25 m/s2
B. 0.50 m/s2
C. 0.75 m/s2
D. 1.00 m/s2

On Mars a rock falls an unknown vertical distance from a resting position and lands in a crater. If it takes the rock 2.5 seconds to fall, how high is the cliff the rock fell from? Mars' surface gravity is 3.8 m/s2.
A. 9.5 m
B. 11.9 m
C. 15.2 m
D. 23.8 m

Answer 2

use these equations
\[a=\frac{ v-v_0 }{ t-t_0 }\]\[d=v_ot+\frac{ 1 }{ 2 }at\]\[v^2=v_0^2+2ad\]\[v=v_0+at\]\[d=\frac{ v_0-v }{ 2 }t\]you should be able to solve for all of them with these equations. i think. also you have to look up mar's acceleration due to gravity.

Answer 3

(3.8 m/s2)?

Answer 4

thank u

Answer 5

didn't know the equations to use, do to being absent.

Answer 6

yeah most of these questions can be answered just by using the first kinematic equation. not the equation for acceleration.

Answer 7

good luck.

Answer 8

thanks again, im closing the question if i have a problem find an answer ill just ask u

Answer 9

criiipes. ok here's a correction for one of the equations. i just realized i forgot a 2nd power on one of the variables. \[d=v_0t+\frac{ 1 }{2 }at^2\]that's the correct equation.