I have 4 science questions.
Sure, what are your science questions?
1. 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 20 km per liter of fuel
a 1,200 kg car that travels 20 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
Answer: The answer is "a 900 kg car that travels 20 km per liter of fuel". It has the highest efficiency by traveling the farthest distance with the least amount of fuel.
2.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 smaller percentage of the energy output of the LED bulb goes toward light.
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.
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.
Answer: The answer is "A greater percentage of the energy output of the incandescent bulb goes toward heat". Incandescent bulbs waste more energy in the form of heat, whereas LED bulbs convert most of their energy into light. Therefore, LED bulbs are more efficient as they produce more light with less energy wasted.
3.What can be done to improve the efficiency of a ramp?(1 point)
Responses
Add a rough surface.
Add a rough surface.
Insulate the surface with foam.
Insulate the surface with foam.
Smooth the surface.
Smooth the surface.
Make it shorter and steeper.
Answer: The answer is "Smooth the surface". By smoothing the surface of the ramp, friction between the ramp and the object being moved is reduced, which makes it easier to move the object up the ramp. This results in greater efficiency of the ramp.
A pulley system is operating at only 50% efficiency. How could the efficiency be increased? (1 point)
Responses
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 reducing the friction on the pulleys
by reducing the friction on the pulleys
by adding more pulleys to the system