The body freely falls from a certain height and at the surface of the earth

The body freely falls from a certain height and at the surface of the earth it reaches a speed of 100m / s from what height the body fell, how long did it fall.

In order to find the fall time, we use the equation

v = v0 + a * t,

Where,

v – body speed, v0 – initial speed, a – acceleration, t – motion time.

Since the body falls freely, then v0 = 0 (m / s).

v = a * t,

The body moves in the gravitational field of the Earth, therefore a = g = 10 (m / s2).

From the last equation we find t:

t = v / a = v / g,

t = 100/10 = 10 (c).

In order to find the height, we will use the equation:

h = v0 * t + a * t ^ 2/2,

in this equation:

v0 – initial speed,

a – acceleration,

t – time,

or,

h = v0 * t + g * t ^ 2/2,

h = g * t ^ 2/2.

Substitute the numerical values:

h = g * t ^ 2/2 = 10 * 10 ^ 2/2 = 1000/2 = 500 (m).

Answer: t = 10 (c); h = 500 (m).