Which of the following best describes the sum of all forces acting on an object?(1 point)

Question

Responses

net force, which is a vector sum
net force, which is a vector sum

gravitational force, which is a vector sum
gravitational force, which is a vector sum

net force, which is a scalar sum
net force, which is a scalar sum

acceleration, which is a vector sum

Suppose a man is sitting on a chair and exerting 100 N of force downward, while a spring beneath the chair exerts 150 N of force upward. If you assign a negative value to the downward force, what is the net force of this system?(1 point)
Responses

50 N
50 N

50 kg
50 kg

-50 N
-50 N

250 N

During a game of pool, a cue ball travels to the left with 70 N of force and collides with the four ball moving with a force of 50 N to the right. If you assign a negative value to the force moving to the right, what is the net force of this system?(1 point)
Responses

20 N
20 N

-20 N
-20 N

120 N
120 N

20 m/s2

Recall that the formula for momentum is:

P=mv

Which of the following correctly shows momentum being calculated?

(1 point)
Responses

14 kg*/s=(9 kg) (5 m/s)s
14 kg * / s = ( 9 kg ) ( 5 m / s ) s

45 kg*m/s=(9 kg) (5 m/s)
45 kg * m / s = ( 9 kg ) ( 5 m / s )

4 kg*m/s=(9 kg) (5 m/s)
4 kg * m / s = ( 9 kg ) ( 5 m / s )

45 N=(9 kg) (5 m/s)

A hockey puck with a mass of 0.12 kg is traveling across the ice at a velocity of 150 m/s downfield. What is the momentum of the hockey puck?(1 point)
Responses

P=8*10−4 kg*m/s
P = 8 * 10 - 4 kg * m / s

M=18 kg*m/s
M = 18 kg * m / s

P=18 kg*m/s
P = 18 kg * m / s

P=18 N

Answer 1

Here are the answers to each question:

1. Which of the following best describes the sum of all forces acting on an object?

   • Response: net force, which is a vector sum

2. Suppose a man is sitting on a chair and exerting 100 N of force downward, while a spring beneath the chair exerts 150 N of force upward. If you assign a negative value to the downward force, what is the net force of this system?

   • Response: 50 N
     (Calculation: Net force = Upward force - Downward force = 150 N - 100 N = 50 N)

3. During a game of pool, a cue ball travels to the left with 70 N of force and collides with the four ball moving with a force of 50 N to the right. If you assign a negative value to the force moving to the right, what is the net force of this system?

   • Response: 20 N
     (Calculation: Net force = Left force - Right force = 70 N - 50 N = 20 N)

4. Recall that the formula for momentum is: P=mv. Which of the following correctly shows momentum being calculated?

   • Response: 45 kgm/s=(9 kg) (5 m/s)
     (Calculation: P = mv = 9 kg * 5 m/s = 45 kgm/s)

5. A hockey puck with a mass of 0.12 kg is traveling across the ice at a velocity of 150 m/s downfield. What is the momentum of the hockey puck?

   • Response: P=18 kgm/s
     (Calculation: P = mv = 0.12 kg * 150 m/s = 18 kgm/s)

So the final answers are:

1. net force, which is a vector sum
2. 50 N
3. 20 N
4. 45 kg*m/s=(9 kg) (5 m/s)
5. P=18 kg*m/s