Question

A body is projected from the ground at an angle of 45° with the horizontal. Its velocity after \(2\) \(s\) is \(20\) \(ms^{–1}\). The maximum height reached by the body during its motion is ________ m. (use \(g\) = \(10\) \(ms^{–2}\))

Answer 1

Correct Answer: 20

The maximum height reached by the body :

\(⇒ v cosα = u cos\;45°\) …(i)

\(v sinα = u\;sin\;45° – gt\) …(ii)

\(u = 20 \sqrt2\) \(m/s\)

\(⇒ H = \frac{u^2\;sin^2\;45\degree}{20}\)

\(= 20 m\)