Answer:
B
Explanation:
Heat increase molecular motion
Given that,
Initial velocity , Vi = 0
Final velocity , Vf = 40 m/s
Acceleration due to gravity , a = 9.81 m/s²
Distance can be calculated as,
2as = Vf² - Vi²
2 * 9.81 *s = 40² - 0²
s = 81.55 m
For half height, that is, s = 40.77m
Vf= ??
2as = Vf² - Vi²
2 * 9.81 * 40.77 = Vf² - 0²
Vf² = 800
Vf = 28.28 m/s
Therefore, speed of roller coaster when height is half of its starting point will be 28 m/s.
<span>The shortening velocity refers to the speed of the contraction from the muscle shortening while lifting a load. Maximal shortening velocity is only attained with a minimal load. With a light load, the shortening velocity is at its Maximal shortening velocity. When the weight is heavy, the speed in which the muscle lifts the weight decreases in speed at a slower velocity.</span>
Direction!
Velocity is a vector quantity and speed is a scalar quantity. Vector quantities includes both magnitude and direction, while scalar quantities only have magnitude. :)
Answer:
So the ratio will be 
Explanation:
We have given heat engine absorbs 450 joule from high temperature reservoir
So 
As the heat engine expels 290 j
So work done W = 290 J
We know that efficiency 
It is given that efficiency of the engine only 55 % of Carnot engine
So efficiency of Carnot engine 
Efficiency of Carnot engine is 
