Question

A ball is thrown vertically upwards with a speed of 120 m/s. It's speed at midpoint of its path is?

Answer 1

Initial speed of the ball = 120 m/s.

Final Speed of the ball = 0 m/s.

Acceleration =  -g.

Using the formula,

v - u = at

-gt = 0 - 120

gt = 120

t = 12 seconds.

Now, This is the total time. But we want the speed at the mid point.

So Time = 12/2 = 6 seconds.

Using the equation,

v - u = at

∴ v - 120 = -10 × 6

v = 120 - 60

v = 60 m/s.

Hence, the velocity at the midpoint of the path is 60 m/s.

Hope it helps.

Answer 2

Answer:

Speed at midpoint of path = 60.2m/s

Step-by-step explanation:

Given that a ball is thrown upward

Initial Speed of the ball = v=120 m/s

We need to find:

Speed at midpoint of the path = $v_{m}$ =?

As we know

Speed of ball at the highest point = u = 0

So, using

u = v + at

as, a = -g

so,

u = v - gt

substituting the values

0 = 120 - (9.8)t

9.8t = 120

t = 120/9.8

t = 12.2 seconds

Now, we have to find

Time to reach at midpoint of path = t/2 = 6.1 sec

Now using the formula

u = v - gt

u = 120 - (9.8)(6.1)

u = 120 - 59.8

u = 60.2 m/s

So, speed at midpoint of path would be 60.2m/s