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5.Mechanics use a pulley to lift an engine out of a car. How could they make the pulley more efficient?(1 point)
Responses

raise the pulley’s wheel
raise the pulley’s wheel

use a longer rope or cable
use a longer rope or cable

clean and oil the pulley’s axle
clean and oil the pulley’s axle

lower the pulley’s wheel
4Which is an example of a simple machine?(1 point)
Responses

oven
oven

LED lightbulb
LED lightbulb

lawnmower
lawnmower

ramp leading to door
ramp leading to door
3.Lenore is on an inclined plane next to her truck. Holding her hands steady, she pushes a box up the plane and into her truck. Where can energy be lost?(1 point)
Responses

Friction between Lenore’s hands and the box.
Friction between Lenore’s hands and the box.

Friction between Lenore and the ground.
Friction between Lenore and the ground.

Friction between the truck and the inclined plane.
Friction between the truck and the inclined plane.

Friction between the box and the inclined plane.
2.When a science teacher talks about a machine’s efficiency, what is she comparing?(1 point)
Responses

the non-useful energy put out by the machine and the useful energy put out by the machine
the non-useful energy put out by the machine and the useful energy put out by the machine

the thermal energy put out by the machine and the energy put into the machine
the thermal energy put out by the machine and the energy put into the machine

the non-useful energy put out by the machine and the energy put into the machine
the non-useful energy put out by the machine and the energy put into the machine

the useful energy put out by the machine and the energy put into the machine
1.Which is the equation for a machine’s efficiency?(1 point)
Responses

Efficiency=input energy−output energy

cap efficiency is equal to input energy minus output energy

Efficiency=input energyoutput energy ⋅ 100

efficiency is equals to input energy over output energy into 100

Efficiency=input energy+output energy

cap efficiency is equal to input energy plus output energy

Efficiency=output energyinput energy . 100

All Answers 1

Answered by GPT-5 mini AI
1. Efficiency = output energy / input energy ⋅ 100

2. the useful energy put out by the machine and the energy put into the machine

3. Friction between the box and the inclined plane.

4. ramp leading to door

5. clean and oil the pulley’s axle