Answer:
The child will take 5.952 seconds to travel from the top of the hill to the bottom.
Explanation:
Given that the child accelerates uniformly and that both initial (
) and final speeds (
), measured in meters per second, and acceleration (
), measured in meters per square second, are known, we proceed to use the following kinematic equation to determine the time taken to travel from the top of the hill to the bottom (
), measured in seconds, is:
(1)
If we know that 
, 
and 
, then the time taken is:
The child will take 5.952 seconds to travel from the top of the hill to the bottom.
All machines are not 100% efficient because of <span>C. Friction</span>
This is a statement not a question .
Answer:
There's one or two reasons, depending on what is meant by "wind-powered car".
The first reason is that it's impossible for any transfer of energy to be 100% efficient. There will always be frictional losses.
Secondly, if the company means that they want to attach a wind turbine to the car so that the car is powered by the same wind that it generates, that violates the conservation of energy.
