Question

A ball dropped from a height. Find (a) Acceleration (b) Distance after 3 seconds (c) Time in air if final velocity is 20 m/s.

Answer 1

Step-by-step explanation:

Given:

t = 3 s

V = 20 m/s

__________

a - ?

D(t) - ?

t* - ?

1)

The acceleration is equal to the free fall acceleration:

a = g = 9.8 m/s²

2)

Distance after 3 seconds (c) :

D(t) = g·t² / 2

D(3) = 9.8·3² / 2 ≈ 44 m

3)

Time:

V = a·t*

t* = V / a = 20 / 9.8 ≈ 2 s

Answer 2

a)10m/s^2

b)90m/s

c)2seconds

Step-by-step explanation:

a)because the ball is falling, acceleration=gravitational acceleration i.e 10m/s^2

b)distance=velocity x time

velocity= acceleration x time

velocity= 10x3=30m/s

distance= 30x3=90m/s

c)velocity=accelerationxtime

20=10 x t

20=10t

t=20/10

t= 2seconds