Name ______Date ______Period ______

Lab 9 Physics, Constant Velocity and Constant Acceleration Study Guide

In the space provided, write the letter of the choice that best completes the statement or answers the question.

_____1. If a wind surfer changes speed or direction or both speed and direction, you can say that she:

a.is motionless. b.is in constant velocity. c.has accelerated. d.had a change of heart.

_____2. A little red Corvette toy car rolling down an inclined track can have an acceleration of 400

a.cm/cm/sec. b.sec/sec/cm. c.cm/sec. d.cm/sec/sec.

_____3. Toby glances at the speedometer on his bicycle as he begins to coast downhill (not pedaling). He is traveling at 12 miles per hour when he initially and 20 miles per hour exactly 4 seconds later. His acceleration is:

a.2 mph every sec. b.3 mph every sec. c.5 mph every sec. d.8 mph every sec.

_____4. The slope of a position versus time graph represents speed. The slope of a speed versus time graph represents:

a.acceleration. b.force. c.position. d.speed.

Use the graph at right to answer the following questions:

____ 4. What is the acceleration?

a. / –0.5 m/s/s / c. / 1.5 m/s/s
b. / 4 m/s/s / d. / 2.5 m/s/s

____ 5. What is the initial velocity of the object?

a. / 0 m/s / c. / 3 m/s
b. / 1 m/s / d. / 4 m/s

_____6. Which of the following is an example of acceleration?

a.A biker is moving at 2 m/s and increases her speed to 10 m/s.

b.A football player is running at a speed of 8 m/s toward the end zone.

c.A swimmer swims at a constant speed of 3 m/s.

d.None of the above.

_____7. A car that is accelerates at 2 km/hr/second is:

a.traveling 2 km each second.

b.traveling 2 km/hr at each second

c.increasing its velocity at 2 km/hr every hour.

d.increasing its velocity at 2 km/hr every second.

_____8. Which of the following is an example of an acceleration of 0 m/s/s?

a.A swinging tennis racket is moving at 3 m/s and increases its speed to 13 m/s.

b.A jockey is riding on his horse at a speed of 20 m/s and comes to a stop after the end of the race.

c.A skydiver falls at a constant speed of 5 m/s.

d.None of the above.

Constant Velocity Problems

Solve, Use the problem solving boxes.

1. A train travels 225 km in 2.5 hours. What is the train’s average velocity?

Looking for / Solution
Given
Formula

2. You ride your bike for a distance of 30 km. You travel at a velocity of 0.75 km/min.

How long does this take?

Looking for / Solution
Given
Formula

3. A canoeist paddles at an average velocity of 4 km/h for 1hour and 30 minutes.

How far does she travel?

Looking for / Solution
Given
Formula

4. a. Plot the points, b. Draw line of best fit. c. Calculate the slope.

Time (s) / Position (cm)
0 / 10
1 / 16
2 / 20
3 / 24
4 / 30

Constant Acceleration Problems

5. The following refer to the diagram above that shows the motion map for a rolling ball,

a. What is the ball’s acceleration?

b. In what direction is the ball accelerating?

c. Describe the motion of the ball. (what changes, by how much, how often?)

6. A runner is moving at 9 m/s when she begins to slow down at 3 m/s/s. Complete the following.

Velocity vs. Time Graph: At what time will her velocity = 0 m/s?

7. A formula 1 race car takes off from the starting line. The table below shows how his speed changes during the first lap.

a. Complete the table

b. Determine the acceleration.

c. Describe the motion without using the term “acceleration”.

Time (s) / Velocity (m/s)
0 / 0
1 / 8
2 / 16
3
4
5
/ Acceleration = ______
Describe the motion:

8. A hockey puck slides across the ice towards the goal with a speed of 20 m/s. At time = 0s, the puck accelerates at -2 m/s/s. Complete the table.

a. Complete the table

b. Describe the motion without using the term “acceleration”.

Time (s) / Velocity (m/s)
0
1
2
3
4
5
/ Acceleration = _-2 m/s/s ______
Describe the motion:

9. Define acceleration in three ways. (a. graphically, b. verbally, c. in a mathematical equation)


Remember: a = (v2 – v1)/ t v2 = v1 + at

10. After crossing the finish line in a sprint, a runner slows her speed from 9 m/s to 0 m/s in 3 s.

What is her acceleration?

Looking For / Solution-(Show relationships, substitutions, solutions, and units)
Given
formula

11. An instrument is dropped from the top of a rock on Mars. It accelerates in free fall at 4 m/s/s. What is its velocity 5 seconds after it is released?

Looking For / Solution-(Show relationships, substitutions, solutions, and units)
Given
Formula

Lp2.2.4rvwx_accel_17.docx