NEETPhysicsMotion in Two Dimensions
Given below are two statements. One is labelled as Assertion A and the other is labelled as Reason R. Assertion A: Two identical balls A and B thrown with same velocity ' u ' at two different angles with horizontal attained the same range R . If A and B reached the maximum height h 1 and h 2 respectively, then R = 4 h 1 h 2 Reason R: Product of said heights. h 1 h 2 = u 2 sin 2 θ 2 g · u 2 cos 2 θ 2 g
Options
- ABoth A and R are true and R is the correct explanation of A.
- BBoth A and R are true but R is NOT the correct explanation of A.
- CA is true but R is false.
- DA is false but R is true.
Correct answer
A. Both A and R are true and R is the correct explanation of A.
Step-by-step solution
Range of two balls are R 1 = u 2 sin 2 θ 1 g = R 2 = u 2 sin 2 θ 2 g . Now, maximum height by both balls are h 1 = u 2 sin 2 θ 1 2 g and h 2 = u 2 cos 2 θ 2 2 g ∴ h 1 h 2 = u 2 sin 2 θ 2 g u 2 cos 2 θ 2 g = u 2 sin θ cos θ 2 g = R 4 ⇒ R = 4 h 1 h 2 Hence, both A and R are true and R is the correct explanation of A.