Answer:
...
<h2>PE=
<em>work done</em></h2><h2>
<em>m</em><em>gh</em><em>=</em><em>2</em><em>0</em><em>×</em><em>1</em><em>0</em><em>×</em><em>2</em><em>0</em><em>.</em><em>.</em></h2>

.
<em>I </em><em>hope</em><em> </em><em>this</em><em> </em><em>helps</em><em> </em><em>you</em><em>.</em><em>.</em><em>.</em><em>.</em><em>.</em><em>.</em>
Inconsistent. You should take three readings at least.
Answer:
active solar heating systems use solar energy to heat a fluid either liquid or air and then transfer the solar heat directly to the interior space or to a storage system for later use. If the solar system cannot provide adequate space heating, an auxiliary or back-up system provides the additional heat.
hope this helps : )
Answer: 6.12 kg
Explanation:
Since Mass of ball = ? (let the unknown value be Z)
Acceleration due to gravity, g= 9.8m/s^2
Height, h = 1.5 metres
Gravitational potential energy GPE = 90J
Gravitational potential energy depends on the weight of the ball, the action of gravity and height.
Thus, GPE = Mass m x Acceleration due to gravity g x Height h
90J = Z x 9.8m/s^2 x 1.5m
90 = Z x 14.7
Z = 90/14.7
Z = 6.12 kg
Thus, the bowling ball weigh 6.12 kilograms
On the floor because the force from the train moving and she wouldn't be able to catch it in time