A.rock breaking and D movement below ground
thermal energy is the correct answer of number 7
It started that the present is the key to the past. The process that we see in operation today are the same ones that have operated in the geologic past.
Given
The projectile is in air for a time of t=8 sec
To find
The time it takes to reach the highest point
Explanation
A projectile moves up to the highest point and then again moves down following a parabolic path.
So it will reach the highest point at a time half the time it requires to follow teh parabolic path.
The time taken to reach the highest point is 4 sec
Conclusion
The time taken is 4 sec.
KE = 1/2 x 80 x 60^2
KE = 144000
