Two movers are attempting to push a couch up a ramp. One mover applies a force of 80 N to the right, but the force of friction between the couch and the ramp is providing a force of 110 N in the opposite direction, and the couch slides down the ramp.

Question

At minimum, how much force will the second mover need to apply to help push the couch up the ramp?

(1 point)
Responses

80 N
80 N

110 N
110 N

30 N
30 N

31 N

Answer 1

To determine the minimum force that the second mover needs to apply to help push the couch up the ramp, we need to consider the forces acting on the couch.

Currently, one mover is applying a force of 80 N to the right (up the ramp), and the force of friction opposing this motion is 110 N down the ramp.

The net force acting on the couch can be calculated as follows:

Net force = Applied force - Friction force Net force = 80 N (up) - 110 N (down) Net force = 80 N - 110 N = -30 N

This means that the couch is experiencing a net force of 30 N downward (it is sliding down the ramp). Therefore, to overcome this downward force of 30 N and to push the couch up the ramp, the second mover will need to apply a force that is at least equal to this net force.

Thus, the second mover will need to apply at least 30 N in addition to the existing 80 N to achieve a net upward force.

If the second mover applies 30 N, the total applied force would be:

Total applied force = 80 N (first mover) + 30 N (second mover) = 110 N

This would balance out the friction force, allowing the couch to stay still. Therefore, the second mover will need to apply at least:

30 N

to help push the couch up the ramp. Hence, the answer is 30 N.

Answer 2

1 point)In the experimental setup shown, a car has one end of a string attached to it, and the other end is attached to a fixed number of metal discs. The car moves along the table and two probes sense the motion of the car. The probes send information to a computer that displays the acceleration and velocity of the experiment. When looking at these results, which quantity stays constant during the trials?

Responses

acceleration
acceleration

force
force

velocity
velocity

mass

Answer 3

In the experimental setup described, where a car is moving along the table with one end of a string attached to it (and the other end connected to a fixed number of metal discs), the quantity that stays constant during the trials would generally be mass.

Here’s a brief explanation for the options:

• Acceleration: This may change depending on how much force is applied (from the metal discs, tension in the string, etc.) and could vary throughout the trials.
• Force: The force acting on the car can change based on the number of metal discs and other factors, so it is not constant.
• Velocity: While the car is in motion, its velocity can change as it accelerates or decelerates.
• Mass: The mass of the car and the metal discs would remain constant throughout the trials, assuming no additional mass is added or removed.

Therefore, the correct response is:

mass.