Item 1
Two forces have the same magnitude F.
Part A
What is the angle between the two vectors if their sum has a magnitude of 2F? θ = 0∘
Part B
What is the angle between the two vectors if their sum has a magnitude of 2√F? θ = 90∘
Part C
What is the angle between the two vectors if their sum has a magnitude of zero? θ = 180∘
Item 2
An object is moving in the absence of a net force. Which of the following best describes the object's motion?
*The object will continue to move with a constant velocity.
Item 3
An object is moving with constant velocity. Which of the following best describes the force(s) acting on the object?
*The net force acting on the object is zero.
Item 4
A constant net force acts on an object. Which of the following best describes the object's motion?
*The object is moving with a constant acceleration.
Item 5
The same net force is applied to two different objects. The second object has twice the mass of the first object. Compare the acceleration of the two objects.
*The acceleration of object 1 is twice the acceleration of object 2.
Item 6
An object is at rest on a tabletop. Earth pulls downward on this object with a force equal in magnitude to mg. If this force serves as the action force, what is the reaction force in the action–reaction pair?
*The object pulling upward on Earth
Item 7
A large truck collides head-on with a small car. The car is severely damaged as a result of the collision. According to Newton's third law, how do the forces acting between the truck and car compare during the collision?
*The force on the truck is equal to the force on the car.
Item 8
You swing a bat and hit a heavy box with a force of 1500 N. The force the box exerts on the bat is
*Exactly 1500 N whether or not the box moves.
Item 9
A stalled car is being pushed up a hill at constant velocity by three people. The net force on the car is
*Zero
Item 10
In order to get an object moving, you must push harder on it than it pushes back on you.
*False
Item 11
In order to lift a bucket of concrete, you must pull up harder on the bucket than it pulls down on you.
*False
Item 12
A box of mass m is pulled with a constant acceleration a along a horizontal frictionless floor by a wire that makes an angle of 15° above the horizontal. If T is the tension in this wire, then
*T>ma
Item 13
You are standing in a moving bus, facing forward, and you suddenly fall forward as the bus comes to an immediate stop. The force acting on you that causes you to fall forward is
*No forces were acting on you to cause you to fall.
Item 14
Consider what happens when you jump up in the air. Which of the following is the most accurate statement?
*When you push down on the earth with a force greater than your weight, the earth will push back with the same magnitude force and thus propel you into the air.
Item 15
A fish weighing 16 N is weighed using two spring scales, each of negligible weight, as shown in the figure. What will be the readings of the scales?
[pic]
*Each scale will read 16 N
Item 16
An object is moving forward with a constant velocity. Which statement about this object MUST be true?
*The net force on the object is zero.
Item 17
A ball is tossed vertically upward. When it reaches its highest point (before falling back downward)
*The velocity is zero, the acceleration is directed downward, and the force of gravity acting on the ball is directed downward.
Item 18
A car is being towed at constant velocity on a horizontal road using a horizontal chain. The tension in the chain must be equal to the weight of the car in order to maintain constant velocity.
*False
Item 19
Two dogs pull horizontally on ropes attached to a post; the angle between the ropes is 61.0∘. Dog Aexerts a force of 282N and dog B exerts a force of 312N.
Part A
Find the magnitude of the resultant force.
F = 512 N
Part B
Find the angle the resultant force makes with dog A's rope. θ = 32.2 ∘
Item 20
A 1190-kg car is held in place by a light cable on a very smooth (frictionless) ramp, as shown in the figure. The cable makes an angle of 31.0 ∘ above the surface of the ramp, and the ramp itself rises at 25.0 ∘above the horizontal.
Part A
Draw a free-body diagram for the car.
Draw the force vectors with their tails at the front bumper of the car. The location and orientation of your vectors will be graded. The exact length of your vectors will not be graded.
[pic]
Part B
Find the tension in the cable. T = 5760 N
Part C
How hard does the surface of the ramp push on the car? N = 7600 N
Item 21
A large wrecking ball is held in place by two light steel cables (Figure 1).
[pic]
Part A
If the mass m of the wrecking ball is 4090kg , what is the tension TB in the cable that makes an angle of 40∘ with the vertical?
Express your answer using two significant figures.
*52000 N
Part B
If the mass m of the wrecking ball is 4090kg , what is the tension TA in the horizontal cable?
Express your answer using two significant figures.
*34000N
You May Also Find These Documents Helpful
-
(e) The car exerts a force on the truck, but the truck does not exert a force on the car.…
- 2368 Words
- 10 Pages
Good Essays -
2. Inertia-an object at rest will most likely stay at rest, while an object at motion will most likely stay at motion…
- 470 Words
- 2 Pages
Satisfactory Essays -
A block accelerates 3 m/s2 down a plane inclined at angle 27.0◦. The acceleration of gravity is 9.81 m/s2 . 1. The force of the static friction would have a vertical component in this situation, and that is impossible since it must be parallel to the table surface. 2 3 s m/ 2.…
- 5122 Words
- 42 Pages
Satisfactory Essays -
____ 2. Which of the following forces arises from direct physical contact between two objects?…
- 1653 Words
- 7 Pages
Powerful Essays -
A force is continuously applied to an object, causing it to accelerate. After a period of time, however, the object stops accelerating. What conclusion can be drawn?…
- 832 Words
- 4 Pages
Good Essays -
Balanced forces- Equal in size and opposite in direction, cancelling each other out. They do not cause a change in motion.…
- 1586 Words
- 5 Pages
Good Essays -
The force that the baseball exerts on the bat and the force that the bat exerts on the baseball are the same magnitude.…
- 476 Words
- 2 Pages
Satisfactory Essays -
I do not have answers to these problems, and I haven’t thought about how to solve them. They are all fairly challenging and fair game for a test question. Work with friends on them, explain your solutions and convince yourselves that you understand the problems. I can’t tell you if you are right - I just don’t know!…
- 2277 Words
- 6 Pages
Satisfactory Essays -
e) Know and understand that if the resultant force acting on a moving object is:…
- 5301 Words
- 22 Pages
Good Essays -
2. Inertia- When a object is at rest it will remain at rest. While an object in motion will remain in motion in the same direction unless a force touch it.…
- 1581 Words
- 6 Pages
Satisfactory Essays -
- Be sure to note that the ‘system’ always includes both you and the elevator Forces that belong on a free-body diagram Only forces that are being applied to the object should appear on that object’s free-body diagram. We should include a downward normal force, applied to the elevator by you. Yes, mg is numerically equal to this normal force in this case. When the system has an acceleration, however, these forces are no longer equal.…
- 874 Words
- 4 Pages
Good Essays -
Problem 1 . A) What is the direction of the acceleration of an object that is slowing down while heading northward? Answer : The acceleration would be southward since the net force required to cause this acceleration would be southward. The change in velocity is directed southward. B) What is the acceleration of an object thrown straight up in the air, near the surface of the earth, at the very top of its flight? Answer : The acceleration is downwards at 9. 8 m/s 2 . The only force acting on the object at the top of its flight is the gravitational force^ so the object is in free fall. The object is changing velocity as it passes through zero velocity. C) What is the direction of the net force acting on an object that is moving in a circle with constant speed. Answer : As shown in the chapter 3 text, the acceleration of such an object is directed towards the center of the circle so the net force on the object must also be directed towards the center of the circle. D) Is it possible to round a corner with constant velocity? Explain! Answer : No, to round a corner one must change direction and so one must change velocity. E) According to Newton’ s Second Law, more massive objects tend to be harder to accelerate. Why then do all objects, regardless of mass accelerate at the same rate when in free fall? Answer: Although more massive objects are harder to accelerate, the gravitational force is larger on more massive objects. These effects cancel exactly, ( with + y up) ay = Fn et , y − m gE = = − gE m m…
- 3414 Words
- 14 Pages
Powerful Essays -
If object 1 and object 2 interact, the force exerted by object 1 on object 2 is equal in…
- 2192 Words
- 20 Pages
Good Essays -
The behavior of all objects can be described by saying that objects tend to "keep on doing what they're doing" (unless acted upon by an unbalanced force). If at rest, they will continue in this same state of rest. If in motion with an eastward velocity of 5 m/s, they will continue in this same state of motion (5 m/s, East). If in motion with a leftward velocity of 2 m/s, they will continue in this same state of motion (2 m/s, left). The state of motion of an object is maintained as long as the object is not acted upon by an unbalanced force. All objects resist changes in their state of motion - they tend to "keep on doing what they're doing."…
- 1800 Words
- 8 Pages
Better Essays -
Another example that you see something similar for an action/ reaction pair is, when a baseball bat strikes a ball. There's no doubt the bat applies a force to the ball: It accelerates rapidly after being struck. But the ball must also be applying a force to the bat. The mass of the ball, however, is small compared to the mass of the bat, which includes the batter attached to the end of it. Still, if you've ever seen a wooden baseball bat break into pieces as it strikes a ball, then you've seen firsthand evidence of the ball's force.…
- 390 Words
- 2 Pages
Satisfactory Essays