<em>if the object has 0 potential energy it means it is on ground ..
<u>explanation :
</u>to measure potential energy we take ground as a reference point but when object is placed on reference point i.e ground then height is 0..
as potential energy = mgh .. here h becomes 0 so potential energy is 0 joules..</em>
Answer:
How long does the ball fall is t_2 = 13.66 (s).
From what height is the ball originally dropped is h= 913.90 (m).
Explanation:
Answer:
19.62 ms
Explanation:
t = Time taken = 2 s
u = Initial velocity
v = Final velocity
s = Displacement
a = Acceleration due to gravity = 9.81 m/s² (downward direction is taken as positive)
Equation of motion

The speed of the pebble when it hit the water is 19.62 ms
Explanation:
a)
Sum of moments = 0 (Equilibrium)
T . cos (Q)*L = m*g*L/2



b) If the String is shorter the Q increases; hence, Cos Q decreases which in turn increases Tension in the string due to inverse relationship!
c)

Answer:
The total power associated with sunlight shining on the Earth is 8.04 × 10^10W
Explanation: Please see the attachment below