Explanation:
Given that,
The mass of rock, m = 2.35-kg
It was released from rest at a height of 21.4 m.
(a) The kinetic energy is given by : 
As the rock was at rest initially, it means, its kinetic energy is equal to 0.
(b) The gravitational potential energy is given by : 
It can be calculated as :

(c) The mechanical energy is equal to the sum of kinetic and potential energy such that,
M = 0 J + 492.84 J
M = 492.84 J
Hence, this is the required solution.
Answer:
It is d. 0.80
Trust me i got it right took it and got it right
Answer:
Force=7.71KN in the opposite direction
Explanation:
Given the mass of the car(M)=1000Kg
The initial speed of the car(u)=100km/hr
we know that 1km/hr=5/18 m/sec
100km/hr=100*5/18 m/sec=27.77m/sec
the distance travelled before it stops (s)=50m
let the acceleration of the car be a
The final velocity of the car is 0.
we know that 

a=7.712m/
We know that F=Ma
F=1000* 7.712=7712N=7.71KN
Answer:
Acceleration acts always in the direction. Of the displacement. Of the initial velocity.
answer:
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