Question

Free Fall Problems

1.)
A pencil is dropped from the top of a very tall bridge and hits the ground 3.2 s later
A) With what velocity did the pencil hit the river below?
B.)
How far did the pencil fall?||

Answer 1

50.2m

Step-by-step explanation:

Given parameters:

Time taken for the pencil to hit the ground = 3.2s

Unknown:

Final velocity = ?

height of fall = ?

Solution:

To solve this problem, we should apply appropriate motion equations;

A.

V = U + gt

V is the final velocity

U is the initial velocity

g is the acceleration due to gravity

t is the time taken

Insert the parameters and solve;

V = 0 + 9.8 x 3.2 = 31.36m/s

B.

h = ut +
`(1)/(2)`gt²

h is the height of fall

Insert the parameters and solve;

h =
`(1)/(2)` x 9.8 x 3.2² = 50.2m