A rock of mass 200kg is dropped from a height of 200m. What is the Kinetic energy at: a) 0 seconds
b) 2 seconds
c) 4 seconds
d) just before it hits the ground

Explanation:

1.

M=200kg

H=200m

for 0 second

now

ke=1/2mv^2

=1/2 .200.200/0

=40000/2

=20000 kgm/ s

2.

for 2second

now

ke=1/2mv^2

=1/2.200.200/2

=40000/4

=10000 kgm/s

3.

for 4second

now

ke= 1/2mv^2

=1/2.200.200/4

=40000/8

=5000 kgm/s

because it says use -2,0,and 2 for x, we can plug those numbers into the equation. y/4=3/4(-2)+2   y/4= -1 1/2 +2 now to get x by itself, we can multiply each side by 4. y=-6+8 which equals y=2 when x=-2. now you can do the same thing with 0 and 2 as x. you get y=8 when x=0 and y=14 when x=2.

x   |   y

-2 |   2

0   |   8

2   |   14

he made 11 calls in one day