According to the conservation of mechanical energy, the kinetic energy just before the ball strikes the ground is equal to the potential energy just before it fell.
Therefore, we can say KE = PE
We know that PE = m·g·h
Which means KE = m·g·h
We can solve for h:
h = KE / m·g
= 20 / (0.15 · 9.8)
= 13.6m
The correct answer is: the ball has fallen from a height of 13.6m.
Answer: The cylinder
Explanation:
Among all other solid shapes, the sphere has the smallest area for a given volume.
By experiment, the ratio of the radius of a sphere to a cylinder of equal volume is less than 1.
Recall;
That the Rate of transfer of convective heat (Q) = h × A ×change in temperature.
Where ,
h= the co efficient of convective heat transfer
A= the cross sectional area.
As such, since the sphere has a smaller surface area relative to the cylinder, the sphere transfers heat slower than the cylinder.
Therefore, if the sphere and cylinder are exposed to convection in the same environment, then, the cylinder cools faster.
PS; the more the Area, the higher the rate of heat transfer and vice versa.
I would say D) melting point.
