A player throws a ball upwards with an initial speed of 30 m s-1. How long does the ball take to return to the players hands? (Take g = 10 m s-2)

Question

A player throws a ball upwards with an initial speed of 30 m s-1. How long does the ball take to return to the players hands? (Take g = 10 m s-2) (A) 3 s (B) 6 s (C) 9 s (D) 12 s

Tardigrade Admin · Accepted Answer

Let t be time taken by the ball to reach the highest point. <img class="img-fluid question-image" alt="image" src="https://cdn.tardigrade.in/img/question/physics/53a23fca49fbb31772f6c1bb8dd06e7b-.jpeg" /> As v = u + at Here, u = 30 m s-1 v = 0 (At highest point velocity is zero) a = - g = -10 m s-2 ∴ 0=30-10t or t=3 s ∴ Time taken by the ball to return to players hand = 3s + 3s = 6 s.

Q. A player throws a ball upwards with an initial speed of $30 m s^{- 1}$ . How long does the ball take to return to the players hands? (Take $g = 10 m s^{- 2}$ )

$3 s$

$6 s$

$9 s$

$12 s$

Let $t$ be time taken by the ball to reach the highest point.

As $v = u + a t$
Here, $u = 30 m s^{- 1}$
$v = 0$ (At highest point velocity is zero)
$a = - g = - 10 m s^{- 2}$
$∴ 0 = 30 - 10 t$ or $t = 3 s$
$∴$ Time taken by the ball to return to players hand $= 3 s + 3 s = 6 s$ .

Q. A player throws a ball upwards with an initial speed of 30ms−1. How long does the ball take to return to the players hands? (Take g=10ms−2)

3s

6s

9s

12s