Question

During a football game, a student accidentally knocks similar gym bags, one empty and one full of shoes and clothes, off the back of the bleachers. If there is no air resistance, which bag will hit the ground first?(1 point)
Responses

The empty bag will hit the ground first.
The empty bag will hit the ground first.

The full bag will hit the ground first.
The full bag will hit the ground first.

They will both hit the ground at the same time.
They will both hit the ground at the same time.

This cannot be determined because the dimensions of the bags are needed.


Question
Mark weighs 200 Newtons on Earth, where the force of gravity is 10 m/s2. He goes to Mars, where the force of gravity is 3.5 m/s2. What is Mark's weight on Mars?(1 point)
Responses

70 N
70 N

700 N
700 N

570 N
570 N

200 N


Question
You and your friend mow a half acre lawn. You get it done in half the time of your friend. Who did more work? (1 point)
Responses

You, because you did it faster
You, because you did it faster

Your friend, because they did it slower
Your friend, because they did it slower

You both did the same amount of work, because time is not relevant to the work completed
You both did the same amount of work, because time is not relevant to the work completed

None of the above


A lever has a mechanical advantage of 4. If you apply a force to the machine with a mass of 4 kg, at an acceleration of 2 m/s/s, what is the output force created by the lever? Hint: Use the equation Fo=MA*Fi.(1 point)
Responses

0.5 N
0.5 N

0.5 J
0.5 J

32 N
32 N

32 J


By sharpening a wedge, you _______________ the machine’s mechanical advantage.(1 point)
Responses

Increase
Increase

Decrease
Decrease

Do not affect
Do not affect

Lose


If your actual mechanical advantage is 10 J and the theoretical is 40 J, what is your percent efficiency? Hint: % Efficiency = (Actual MA/Ideal MA) * 100(1 point)
Responses

0.25%
0.25%

25%
25%

4%
4%

400%


Oiling bicycle chains or chainsaws is efficient at making the machines work better because the oil reduces _________________________. (1 point)
Responses

Mechanical advantage
Mechanical advantage

Friction
Friction

The number of revolutions the chain needs to do around the gears
The number of revolutions the chain needs to do around the gears

Efficiency


Answers

GPT-4o mini
Here are the answers to the questions you provided:

1. **During a football game, a student accidentally knocks similar gym bags, one empty and one full of shoes and clothes, off the back of the bleachers. If there is no air resistance, which bag will hit the ground first?**
- **Response:** They will both hit the ground at the same time.

2. **Mark weighs 200 Newtons on Earth, where the force of gravity is 10 m/s². He goes to Mars, where the force of gravity is 3.5 m/s². What is Mark's weight on Mars?**
- **Response:** 70 N
- (Weight = mass × gravity; Mark's mass = 200 N / 10 m/s² = 20 kg; Weight on Mars = mass × gravity on Mars = 20 kg × 3.5 m/s² = 70 N)

3. **You and your friend mow a half-acre lawn. You get it done in half the time of your friend. Who did more work?**
- **Response:** You both did the same amount of work, because time is not relevant to the work completed.

4. **A lever has a mechanical advantage of 4. If you apply a force to the machine with a mass of 4 kg, at an acceleration of 2 m/s², what is the output force created by the lever?**
- **Response:** 32 N
- (From the hint: Output force (Fo) = Mechanical Advantage × Input Force (Fi), where Fi = mass × acceleration = 4 kg × 2 m/s² = 8 N; thus, Fo = 4 × 8 N = 32 N)

5. **By sharpening a wedge, you _______________ the machine’s mechanical advantage.**
- **Response:** Increase

6. **If your actual mechanical advantage is 10 J and the theoretical is 40 J, what is your percent efficiency?**
- **Response:** 25%
- (Percent Efficiency = (Actual MA / Ideal MA) × 100 = (10 J / 40 J) × 100 = 25%)

7. **Oiling bicycle chains or chainsaws is efficient at making the machines work better because the oil reduces _________________________.**
- **Response:** Friction

Feel free to ask if you have any more questions!