PHYSICS MOD 1 HW-1.As a baseball is being thrown, it goes from 0.0 to 40.0 m/s in 0.26 s.
Subject: Physics   / General Physics
Question
1. As a baseball is being thrown, it goes from 0.0 to 40.0 m/s in 0.26 s.
(a) What is the acceleration of the baseball?
(b) What is the acceleration in g’s?
2. A child sits on the edge of a spinning merry-go-round that has a radius of 1.6
m. The child’s speed is 5 m/s. What is the child’s acceleration?
3. During a NASCAR race a car goes 90 m/s around a curved section of track
that has a radius of 240 m. What is the car’s acceleration?
4. Initially stationary (the train starts at rest), a train has a constant acceleration
of 0.7 m/s2.
(a) What is its speed after 40 s?
(b) What would be the total time it would take to reach a speed of 49 m/s?
5. A rock is dropped off the side of a bridge and hits the water below 7.7 s later.
(a) What was the rock’s velocity when it hit the water?
speed
direction
(b) What was the rock’s average velocity as it fell?
speed
direction
(c) What is the height of the bridge above the water?
7. During takeoff, an airplane goes from 0 to 72 m/s in 10 s.
(a) What is its acceleration?
(b) How fast is it going after 4 s?
(c) How far has it traveled by the time it reaches 72 m/s?
8. A high-performance sports car can go from 0 to 100 mph in 9.4 s. (Assume the
car travels in the positive direction. Indicate the direction with the sign of your
answer.)
(a) What is the car’s average acceleration (in SI units; meter-kilogramsecond)?
(b) The same car can come to a complete stop from 27 m/s in 5.9 s. What is its
average acceleration?
9. A passenger jet flies from one airport to another 1,373 miles away in 3.0 h.
Find its average speed in the mks system of units.
10. What are the “basic” or “fundamental” physical quantities? (Select all that
apply.)
time
distance
area
mass
speed
11. List the physical quantities identified in this chapter. From which of the
fundamental physical quantities is each derived? Which of them are vectors, and
which are scalars?
12. What is the distinction between speed and velocity? Describe a situation in
which an object’s speed is constant but its velocity is not.
13. What does the slope of a distance-versus-time graph represent physically?
area
acceleration
velocity
displacement
time
