134k views
2 votes
A ball is thrown straight upwards at a speed of 40 m/s. (assume

no air resistance)
How long does it take to stop?
a) 1 sec
b) 2 sec
c) 3 sec
d) 4 sec
e) 5 sec

1 Answer

5 votes

Final answer:

The ball takes approximately 4.08 seconds to stop.

Step-by-step explanation:

To determine how long it takes for the ball to stop, we need to first understand the motion of the ball. When a ball is thrown straight upwards, it experiences a constant acceleration due to gravity pulling it downwards. The initial velocity is 40 m/s. The final velocity when it stops momentarily is 0 m/s.

Using the equation v = u + at, where v is the final velocity, u is the initial velocity, a is the acceleration, and t is the time, we can rearrange the equation to solve for time t. In this case, u = 40 m/s, v = 0 m/s, and a = -9.8 m/s² (acceleration due to gravity).

0 = 40 + (-9.8)t

-40 = -9.8t

t = -40 / -9.8

t ≈ 4.08 s

Therefore, it takes approximately 4.08 seconds for the ball to stop. Since this is not one of the given options, we can conclude that none of the provided options, a) 1 sec, b) 2 sec, c) 3 sec, d) 4 sec, or e) 5 sec, is correct.

User YasserKaddour
by
7.7k points

No related questions found

Welcome to QAmmunity.org, where you can ask questions and receive answers from other members of our community.

9.4m questions

12.2m answers

Categories