Answer :
After 0.85s, the ball would be at the same height.
Calculation
A ball is thrown upward from the ground with an initial speed of 23.4 m/s; at the same instant, another ball is dropped from a building 20 m high....
We know that from the equation of motion,
h = u t + 1/2 at^2
So h = height, u is initial velocity and t is time, a is acceleration
Now for the ball thrown upwards
h = 23.4 t – 1/2 gt^2
23.4 t – h = 1/2 gt^2
Now for the ball dropped downwards
20– h = 1/2 gt^2
Comparing both the equations we get
23.4t – h = 20 – h
23.4 t = 20
So t = 20/23.4
Or t = 0.85 secs
The balls will be at same height when t = 0.85 s
Motion under gravity
Gravity causes a body to descend faster, and as it does, the air resistance that slows it down rises.
This keeps happening until the weight of the object and the force of air resistance are equal. The terminal velocity is the pace at which the item now falls instead of accelerating any longer.
What do you mean by motion in a gravitational field?
When any object moves, it is said to be in motion under gravity. This is because gravity has an impact on the object’s vertical motion.
Gravity is the force that pulls things downward. In actuality, gravity pulls objects toward the Earth’s center.
To know more about motion under gravity visit:
https://brainly.com/question/13194563
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