Question

A body falls freely from rest. Find;

a. distance it falls in 5 sec.

b. velocity after falling 5km.

c. time required to attain a velocity of 50m/s

d. time in which it falls 200m.

Answer 1

a)

$$h=0.5gt^2=0.5(9.8)(5)^2=122.5\ m$$

b)

$$v=\sqrt{2gh}=\sqrt{2(9.8)(5000)}=313\frac{m}{s}$$

c)

$$t=\frac{v}{g}=\frac{50}{9.8}=5.1\ s$$

d)

$$T=\sqrt{\frac{2h}{g}}=\sqrt{\frac{2(200)}{9.8}}=6.4\ s$$