Forum

A car starts from r...
 
Notifications
Clear all

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.

1 Posts
2 Users
0 Likes
418 Views
0
Topic starter

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? (Take g = 10 m/s2)

(1) 20 m/s, 5 m/s2

(2) 20 m/s, 0

(3) 20√2 m/s, 0

(4) 20√2 m/s, 10m/s2

1 Answer
0

The answer is (4) 20√2 m/s, 10m/s2

Explanation:

Velocity of car at t = 4 sec

v = u + at

v = 0 + 5(4)

= 20 m/s

At t = 6 sec

Acceleration is due to gravity

∴ a = g = 10 m/s

vx = 20 m/s (due to car)

vy = u + at

= 0 + g(2) (downward)

= 20 m/s (downward)

v = \(\sqrt{v_x^2 + v_y^2}\)

= \(\sqrt{20^2 + 20^2}\)

= 20√2 m/s

This post was modified 2 years ago by admin
Share:

How Can We Help?