Question

A person pushes a box. He applies a force of 400 newtons, and he pushes the box for a distance of 4 meters. After he stops pushing, the box slides forward another meter. How much work was done by the person? (1 point)

• 2,000 joules
• 1,600 joules
• 400 joules
• 100 joules

Answer 1

[AI-generated answer — Bot GPT 3.5]

The work done by a person is calculated using the formula:

Work = Force * Distance

Given:
Force = 400 newtons
Distance pushed = 4 meters
Distance slid after pushing stopped = 1 meter

Work done while pushing = Force * Distance
= 400 newtons * 4 meters
= 1600 joules

Work done after pushing stopped = Force * Distance
= 400 newtons * 1 meter
= 400 joules

Total work done = Work done while pushing + Work done after pushing stopped
= 1600 joules + 400 joules
= 2000 joules

Therefore, the correct answer is:
• 2,000 joules

Answer 2

In this pulley system, the pulleys will ? the mechanical force required to lift the block and will change the ?.

(1 point)
• decrease; weight of the block
• decrease; direction of the force
• increase; weight of the block
• increase; direction of the force

Answer 3

[AI-generated answer — Bot GPT 3.5]

• decrease; weight of the block

In a pulley system, the mechanical advantage increases as the number of pulleys increase, making it easier to lift an object. The pulleys will decrease the mechanical force required to lift the block by distributing the force over multiple ropes and pulleys. This, in effect, decreases the weight of the block that needs to be lifted by the person.

Answer 4

Which list correctly orders effort (E), fulcrum (F), and load (L) for each lever class? (1 point)

• class 1 = F, E, L (or L, E, F)
class 2 = F, L, E (or E, L, F)
class 3 = L, F, E (or E, F, L)

• class 1 = F, E, L (or L, E, F)
class 2 = L, F, E (or E, F, L)
class 3 = F, L, E (or E, L, F)

• class 1 = F, L, E (or E, L, F)
class 2 = F, E, L (or L, E, F)
class 3 = L, F, E (or E, F, L)

• class 1 = L, F, E (or E, F, L)
class 2 = F, L, E (or E, L, F)
class 3 = F, E, L (or L, E, F)

Answer 5

[AI-generated answer — Bot GPT 3.5]

• class 1 = F, E, L (or L, E, F)

class 2 = L, F, E (or E, F, L)
class 3 = F, L, E (or E, L, F)

Answer 6

How do simple machines make work easier? (1 point)

• They reduce the amount of force needed to move an object to do the same amount of work.
• They magnify the force being applied, thereby decreasing the work they can do with no extra energy exerted by the person using the machine.
• They increase the distance over which a force is needed, doing more work with less force.
• They decrease the distance needed between a person and an object, allowing the person to apply more force and do more work.

Answer 7

[AI-generated answer — Bot GPT 3.5]

• They reduce the amount of force needed to move an object to do the same amount of work.

Answer 8

A person applies 98 Newtons of force to a 20 kilogram box. They apply the force to the box over a 4-meter ramp, raising the box 2 meters from the ground. How much work is done? (1 point)

• 392 Joules
• 80 Joules
• 40 Joules
• 194 Joules

Answer 9

[AI-generated answer — Bot GPT 3.5]

The work done by a person is calculated using the formula:

Work = Force * Distance

Given:
Force = 98 newtons
Distance pushed = 4 meters
Height lifted = 2 meters

Work done = Force * Distance
= 98 newtons * 4 meters
= 392 joules

Therefore, the correct answer is:
• 392 Joules

Answer 10

A person is lifting a heavy box using a lever. What is the purpose of the lever in this situation? (1 point)

• to reduce the energy needed to lift the box and change the direction of the force
• to reduce the force needed to lift the box and change the direction of the force
• to reduce the energy needed to lift the box while keeping the direction of the force the same
• to reduce the force needed to lift the box while keeping the direction of the force the same

Answer 11

[AI-generated answer — Bot GPT 3.5]

• to reduce the force needed to lift the box while keeping the direction of the force the same

The purpose of a lever in this situation is to reduce the amount of force needed to lift the box by increasing the distance from the fulcrum, thereby increasing the leverage and making it easier to lift the heavy box. The direction of the force remains the same as the direction of the force applied is still upward to lift the box.