Answer:
0.775 m
Explanation:
As the car collides with the bumper, all the kinetic energy of the car (K) is converted into elastic potential energy of the bumper (U):

where we have
is the spring constant of the bumper
x is the maximum compression of the bumper
is the mass of the car
is the speed of the car
Solving for x, we find the maximum compression of the spring:

Answer:
735 J/kg/C
Explanation:
Q = mcT
943 = (0.447)( c )(2.87)
1.28289c = 943
c = <u>7</u><u>3</u><u>5</u><u> </u><u>J</u><u>/</u><u>k</u><u>g</u><u>/</u><u>C</u><u> </u><u>(</u><u>3</u><u> </u><u>s</u><u>f</u><u>)</u>
I belive it could be 6.5 but I could be wrong
The ball can't reach the speed of 20 m/s in two seconds, unless you THROW it down from the window with a little bit of initial speed. If you just drop it, then the highest speed it can have after two seconds is 19.6 m/s .
If an object starts from rest and its speed after 2 seconds is 20 m/s, then its acceleration is 20/2 = 10 m/s^2 .
(Gravity on Earth is only 9.8 m/s^2.)