Can anyone answer this?

Question

A ball is dropped from a bridge of 122.5metres above a river.After the ball has been falling for two seconds,a second ball is thrown straight down after it.Initial velocity of second ball so that both hit the water at the same time n dat is?
plz expain wid the process.

Answer 1

I'll give you a head start, and we'll see if you can figure it out from there:

First, the givens:

d = height from the ground to the point at which the two balls are released = 122.5 meters

v1 = initial velocity of the first ball = 0
v2 = initial velocity of the second ball
t1 = time ball 1 is dropping (seconds)
t2 = time ball 2 is dropping (seconds)
t2 = (t1)-2 seconds

a = gravitational acceleration = 9.8 m/sec^2

For both balls:

d = vt + at^2

For the first ball, v1 = 0, so d = at1^2

For the second ball, d = v2t2 + at2^2

The distance in both case is the same, so:

at1^2 = d = v2t2 + at2^2

Okay, so here you go: You have the basic equations,so solving is trivial arithmetic:

d = 122.5 meters = (9.8 m/sec^2) (t1)^2

and solve for t1. Once you know t1, then you know that t2 is two seconds less, so with that value you can solve:

d = 122.5 meters = v2t2 + (9.8 m/sec^2)(t2)^2

I leave the rest to you! (And I have calculated the answer if you want to check it)

Answer 2

The mass of the second ball is greater than that of the first.

Answer 3

To work that equation, you need to know how long the first ball took to travel from 'a' to 'b', to work out the metres per second.

Answer 4

You sure do like questions involving speed and acceleration, are you a math or physics teacher?
I like solving some math problems, but I prefer solving problems related to complex numbers or geometry.

Answer 5

one ball is heavier than the other....i e....dropping a ping pong ball first then a bolwing ball....

Answer 6

they will land at the same time

Answer 7

do ur own hw