Question

An object is thrown vertically upwards and rises to a height of 10 m. Calculate,

 i) the velocity with which the object was thrown upwards. 

ii) the time taken by the object to reach the highest point.

Answer 1

i) s = 10 m, v = 0 m/s, a = – g = – 9.8 m/s².

 v² – u² = 2as

0 – u² = 2 × – 9.8 × 10 ⇒ u =\(\sqrt196\) ⇒ u = 14 m/s.

ii) v = u + at 

0 = 14 – 9.8 × t 

t = 1.43 s