Abody falls freely from rest. find (a)its accleration (b) the distance it falls in 3s (c) its speed after falling 70m (d) the time requied to reach a speed of 25 m/sec (e) the time taken to fall 300m.

a) acceleration = 9.81[m/s^2], b) distance = 44.1[m], c) v = 37.05[m/s], d) t= 2.54 [s], e) t = 7.82[s]

Explanation:

a) If the object falls freely its acceleration is equal to the gravity acceleration

a = g = 9.81[m/s^2].

b)

Using the following kinematic equation we can find the distance.

Note: The initial velocity is zero because the body was released without velocity.

c)

Using the following kinematic equation we can find the velocity, with the 70[m] distance.

d)

Using the following equation we can find the time for a 25 [m/s] speed.

e)

The time taken to fall 300[m], can be found using the following equation:

air exerts forces on falling objects near earth’s surface.

explanation:

the term 'free falls' refer to object that are falling towards the earth, in a situation in which gravity is the only force acting on the object.

for an object in free fall, the acceleration is constant (g, the gravitational acceleration), and so the velocity of the object constantly increases.

for objects near earth's surface, there is always another force acting on the object: the resistance due to the air. this force is opposed to the direction of fall of the object, and it is proportional to the velocity of the object, so as the object falls down, this force increases up to a point when it balances the force of gravity, and the object continues its motion at constant velocity (called terminal velocity). since in this case gravity is not the only force acting on the object, we are not in a situation of free fall.