A car starts from rest and accelerates at $5 {m/s}^{2}$ . At $t = 4 s$ , a ball is dropped out of a window by a person sitting in the car. What is the velocity and acceleration of the ball at $t = 6 s$ ?

$(g = 10 {m/s}^{2})$

20 \sqrt{2} m/s, 10 {m/s}^{2}

Right on! Give the BNAT exam to get a 100% scholarship for BYJUS courses

20 m/s, 5 {m/s}^{2}

No worries! We‘ve got your back. Try BYJU‘S free classes today!

20 m/s, 0 {m/s}^{2}

No worries! We‘ve got your back. Try BYJU‘S free classes today!

20 \sqrt{2} m/s, 0 {m/s}^{2}

No worries! We‘ve got your back. Try BYJU‘S free classes today!

Open in App

Solution

The correct option is A $20 \sqrt{2} m/s, 10 {m/s}^{2}$
Velocity of the car at $t = 4 s$ ,

$v = u + a t = 0 + 5 \times 4 = 20 m/s$

The ball is dropped at this instant, this means the horizontal velocity of the ball will be $v_{h} = 20 m/s$ .

This velocity will remain constant as there is no horizontal acceleration.

Now, vertical velocity at $t = 6 s i . e . Δ t = 2 s$ ,

$v_{v} = u_{v} + a_{v} Δ t = 0 + 10 \times 2 = 20 m/s$ .

Further, the net velocity is,

$v_{net} = \sqrt{v_{h}^{2} + v_{v}^{2}} = \sqrt{20^{2} + 20^{2}} = 20 \sqrt{2} m/s$ .

The motion of the ball is under gravity, so,

$a_{net} = 10 {m/s}^{2}$

Hence, option $(A)$ is the correct answer.

Suggest Corrections

Similar questions

Q. A car starts from rest and accelerates at

5 {m/s}^{2}

. At

t = 4 s

, a ball is dropped out of a window by a person sitting in the car. What is the velocity and acceleration of the ball at

t = 6 s

(g = 10 {m/s}^{2})

A ball is in a hot air balloon that starts from rest at t = 0 and accelerates upwards at 2m/s². After 10s, the ball is dropped from the balloon

Draw the a-t graph of the ball from t = $θ$

A ball is in a hot air balloon that starts from rest at t = 0 and accelerates upwards at 2m/s². After 10s, the ball is dropped from the balloon

Draw the a-t graph of the ball from t =0

A ball is in a hot air balloon that starts from rest at t = 0 and accelerates upwards at 2m/s². After 10s, the ball is dropped from the balloon.Draw ball's v - t graph:

A truck starts from rest and accelerates uniformly at 2.0 m s^–2. At t = 10 s, a stone is dropped by a person standing on the top of the truck (6 m high from the ground). What are the (a) velocity, and (b) acceleration of the stone at t = 11 s? (Neglect air resistance.)

Join BYJU'S Learning Program

A car starts from rest and accelerates at 5 m/s2. At t=4 s, a ball is dropped out of a window by a person sitting in the car. What is the velocity and acceleration of the ball at t=6 s? (g=10 m/s2)

A car starts from rest and accelerates at $5 {m/s}^{2}$ . At $t = 4 s$ , a ball is dropped out of a window by a person sitting in the car. What is the velocity and acceleration of the ball at $t = 6 s$ ?

$(g = 10 {m/s}^{2})$