Download Physics 2014-2015: 1st Semester Review and Practice 1. You enter

Physics 2014-2015: 1st Semester Review and Practice
1.
You enter the lab room to find the following materials available:
- large supply of various rubber bands
- stop watch
- protractor
- assorted masses of given values
- meter stick
- bucket of oil
- assorted balloons of varied size
- bucket of water
Using as few or as many of the materials as you choose, write an experimental question that could
lead to an investigation. Identify your independent variable and dependent and control variables.
Question:
Independent variable:
Dependent variable(s):
Control variables:
Questions 2-4. A science class puts wide wheels onto a small cart and lets it roll down an inclined ramp
and then across the floor. They measure the distance the cart travels. The investigation is repeated
using the same cart but this time fitted with narrow wheels.
2. What is the relationship being studied?
A. The effect of the cart mass on the distance the cart travels.
B. The effect of the incline of the ramp on the speed the cart travels.
C. The effect of wheel width on the distance the cart travels.
D. The effect of wheel width on the speed the cart travels.
3. What is the dependent variable?
A. mass of cart
C. angle of incline
B. width of wheels
D. distance cart travels
4. What is the independent variable?
A. mass of cart
B. width of wheels
C. angle of incline
D. distance cart travels
Questions 5-13. To the right is a graph describing the
motion of a toy car.
5. Describe the motion of the toy car for the 9 s
time period. Be specific.
6.
What is the car’s speed from the start to t = 2 s.
Explain how you got this number.
7.
What is the car’s speed from t = 6 s until t = 9 s? Explain how you got this number.
8.
What distance did the car travel during the entire 9 s shown?
9.
What is the car’s displacement after 9 s?
10. Calculate the average speed of the car over the
whole trip.
11. Calculate the car’s average velocity over the
whole trip.
12. Plot a graph of the velocity for the car’s motion
on the grid to the right.
13. Use your velocity graph to determine the
displacement of the car over the entire trip.
Consider the velocity graph shown on
the right for questions 14-18:
v
(m/s)
8
6
4
2
0
0
2
4
6
8
t (s)
14. Describe the motion being represented by the graph in words.
15. Use the graph to determine the acceleration of the moving object.
16. On the graph, represent the displacement of the object from t = 3s to t = 9s. Calculate this
displacement using the graph.
17. Determine the average velocity of this object from t = 3s to t = 9s.
18. Sketch a displacement graph and an acceleration graph representing the same motion.
Position:
Acceleration:
19. Sketch the graphs corresponding to the one given…
20. Which of the following statements does not describe force?
a. Force causes objects at rest to remain stationary.
b. Force causes objects to start moving.
c. Force causes objects to stop moving.
d. Force causes objects to change direction.
21. A free-body diagram represents all of the following except
a. the object.
c. forces exerted by the object.
b. forces as vectors.
d. forces exerted on the object.
22. The free-body diagram shown on the right represents a car being pulled by
a towing cable. In the diagram, which of the following is the gravitational
force acting on the car?
a. 5800 N
c. 14 700 N
b. 775 N
d. 13 690 N
23. Which of the following is the tendency of an object to maintain its state of
motion?
a. acceleration
c. force
b. inertia
d. velocity
24. A car goes forward along a level road at constant velocity. The additional force needed to bring the
car into equilibrium is
a. greater than the normal force times the coefficient of static friction.
b. equal to the normal force times the coefficient of static friction.
c. the normal force times the coefficient of kinetic friction.
d. zero.
25. As an object falls toward Earth,
a. the object does not exert a force on Earth.
b. the object exerts a downward force on Earth.
c. Newton’s third law does not apply.
d. the upward acceleration of Earth is negligible because of its large mass.
26. A hockey stick hits a puck on the ice. Identify an action-reaction pair in this situation.
a. The stick exerts a force on the puck; the puck exerts a force on the stick.
b. The stick exerts a force on the puck; the puck exerts a force on the ice.
c. The puck exerts a force on the stick; the stick exerts a force on the ice.
d. The stick exerts a force on the ice; the ice exerts a force on the puck.
27. A car accelerates from rest at a rate of 4.5 m/s2 for a time of 5.0 s. a) How fast is the car going
after 5.0 s? b) How far does the car travel in this amount of time?
28. Rocket-powered sleds are used to test the human response to acceleration. If a rocket-powered
sled is accelerated from rest to a speed of 444 m/s in 1.8 seconds, then (a) what is the acceleration
and (b) what is the distance that the sled travels?
29. A feather is dropped on the moon from a height of 1.40 meters. The acceleration of gravity on the
moon is 1.67 m/s2. Determine the time for the feather to fall to the surface of the moon.
30. A motorboat accelerates from a velocity of 6.5 m/s to a velocity of 1.5 m/s at a rate of –2.7 m/s 2. (a)
How far did it travel during the acceleration? (b) For how long did it accelerate?
31. A person pushes on a 75 kg desk with a 300 N force acting at 30° angle
above the horizontal. The desk does not move.
a)
Draw a force diagram for the desk.
b)
Determine the component of the pushing force in the x-direction.
c)
Determine the component of the pushing force in the y-direction.
d)
Write the equation that describes the forces that act in the x-direction.
e)
Write the equation that describes the forces which act in the y-direction.
f)
Determine the value of the frictional force acting on the desk.
g)
Determine the value of the normal force.
32. A 25 kg bucket of water is pulled straight up from a well at constant speed. Draw a force diagram
for the bucket and determine the tension in the rope used to pull the bucket up.
33. A 4.0 kg sign hangs from a boom supported by a cable
connected to a wall. The cable makes a 30° angle with the boom.
a) Sketch a force diagram for the sign.
b)
Write an equation that describes forces in the y-direction
c)
Write an equation that describes the forces in the x-direction
d)
How much tension force is in the cable?
e)
How much force does the boom apply to the sign?
34. A 25 kg bucket is pulled straight up from a well with an acceleration of 1.5 m/s 2. Draw a force
diagram for the bucket and determine the tension in the rope used to pull the bucket up.
35. Consider the block on a surface below being pulled and accelerated to the right by an applied
force of 25 N. The coefficient of friction, µ, is 0.30.
5 kg
a)
In the space to the right of the picture, draw a force diagram for the block.
b)
Write the force equation for the vertical direction.
c)
Write the force equation for the horizontal direction.
d)
Calculate the normal force on the block.
e)
Calculate the frictional force acting on the block.
f)
What the acceleration of the block?
36. A bullet is fired horizontally from height of 2 m from the ground. If the bullet travels 300 m before
striking the ground, how fast was the bullet fired?
37. A cannon ball is fired with a speed of 34 m/s at an angle of 17°.
a) How high will it go (maximum height)?
b)
How long will the cannon ball be in the air?
c)
What is the range of the cannon ball?