Answer:
Explanation:
Total energy is constant
E = mgh + ½mv² + Fd
At the top of the slide, all energy is potential
E = mgh + 0 + 0
At the bottom of the slide, all potential energy has converted to kinetic and work of friction.
mgh = ½mv² + W
W = mgh - ½mv²
W = 30.0[(9.81)(2.0) - ½6²]
W = 48.6 J
Efficiency is defined as the measure of the amount of work or energy is conserved in a certain process. At all times, in every process, work or energy is always lost or wasted due to certain interference. Not all work given is converted to useful work or energy. Thus , efficiency is calculated by dividing the energy or work output to the energy or work input then the value is multiplied by 100 to express efficiency as percentage.
Efficiency = work output / work input
Efficiency = (1020 J / 1200 J) = 85%
Answer: A material called moderator is used to slow down the neutrons released during nuclear fission. The source's neutrons have a high speed and energy. The neutrons' speed is slowed by heavy water or graphite moderators.
Explanation:
Answer:
The time taken to complete her run is 1.9 hr.
Explanation:
Speed is a scalar quantity and it is defined as the ratio of distance covered to the time taken to cover that distance. As distance is also a scalar quantity, so the directions given in the problem can be ignored. Thus, the distance covered by the jogger is the sum of kilometers given in problem.
Distance covered = 6+5+4 = 15 km
And the speed is given as 8 km/hr.
So the time taken will be ratio of distance to speed.
So the jogger will take 1.9 hr to complete her run.
