Answer:

Explanation:
Given:
height above which the rock is thrown up, 
initial velocity of projection, 
let the gravity on the other planet be g'
The time taken by the rock to reach the top height on the exoplanet:
where:
final velocity at the top height = 0 
(-ve sign to indicate that acceleration acts opposite to the velocity)

The time taken by the rock to reach the top height on the earth:



Height reached by the rock above the point of throwing on the exoplanet:

where:
final velocity at the top height = 0 


Height reached by the rock above the point of throwing on the earth:



The time taken by the rock to fall from the highest point to the ground on the exoplanet:
(during falling it falls below the cliff)
here:
initial velocity= 0 



Similarly on earth:

Now the required time difference:


Answer:
5.25
Explanation:
tell me if u need an explanation
Answer:
B
Explanation:
Acceleration = rate of change in velocity
a = (21-12)/(0.45) = 20cm/s^2
Can you send a pic of the question
So, the total energy value that has been transferred by work is <u>32 kJ</u>.
<h3>Introduction</h3>
Hi ! In this question, I will help you. <u>Work is the amount of force exerted to cause an object to move a certain distance from its starting point</u>. In physics, the amount of work will be proportional to the increase in force and increase in displacement. Amount of work can be calculated by this equation :

With the following condition :
- W = work (J)
- F = force (N)
- s = shift or displacement (m)
Now, because in this question, the "s" is not directly known, whereas it is known that the initial velocity is zero, the object has an acceleration, and is moving in certain time intervals. Then, use this formula to find the value of "s" !

With the following condition :
- s = shift or displacement (m)
- a = acceleration (m/s²)
- t = interval of the time (s)
<h3>Problem Solving </h3>
We know that :
- a = acceleration = 4 m/s²
- t = interval of the time = 20 s
- m = mass = 10 kg
What was asked :
Step by Step :
- Calculate value of force by multiple m and a



- Calculate value of shift or displacement




- Last, calculate the value of work



So, the total energy value that has been transferred by work is 32 kJ.