Which car has the greatest efficiency?(1 point)
Responses
a 900 kg car that travels 15 km per liter of fuel
a 900 kg car that travels 15 km per liter of fuel
a 1,200 kg car that travels 15 km per liter of fuel
a 1,200 kg car that travels 15 km per liter of fuel
a 900 kg car that travels 20 km per liter of fuel
a 900 kg car that travels 20 km per liter of fuel
a 1,200 kg car that travels 20 km per liter of fuel
Why are incandescent light bulbs considered to be lower efficiency than LED bulbs?(1 point)
Responses
A smaller amount of energy is wasted by the incandescent bulb.
A smaller amount of energy is wasted by the incandescent bulb.
A greater percentage of the energy output of the incandescent bulb goes toward heat.
A greater percentage of the energy output of the incandescent bulb goes toward heat.
A greater amount of energy is required for the same light output from the LED bulb.
A greater amount of energy is required for the same light output from the LED bulb.
A smaller percentage of the energy output of the LED bulb goes toward light.
A greater percentage of the energy output of the incandescent bulb goes toward heat.
What is the name of the fixed point about which a lever rotates?(1 point)
Responses
bar
bar
fulcrum
fulcrum
pulley
pulley
groove
fulcrum
A pulley system is operating at only 50% efficiency. How could the efficiency be increased? (1 point)
Responses
by reducing the friction on the pulleys
by reducing the friction on the pulleys
by having a second person pulling on the rope
by having a second person pulling on the rope
by decreasing the amount of weight being lifted
by decreasing the amount of weight being lifted
by adding more pulleys to the system
by reducing the friction on the pulleys
The car with the greatest efficiency is a 900 kg car that travels 20 km per liter of fuel.
What can be done to improve the efficiency of a ramp?(1 point)
Responses
Smooth the surface.
Smooth the surface.
Add a rough surface.
Add a rough surface.
Make it shorter and steeper.
Make it shorter and steeper.
Insulate the surface with foam.