It's not in motion when the line straight and flat . there's #9
Answer:
à in unit vector notation = 12.26485i + 7.54539j
B in unit vector notation = 16.3516i + 3.11529j
Explanation:
The detailed steps and calculation is shown in the attachment.
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:


To solve this, we are going to use the formula for the kinetic energy of an object:

where

is the kinetic energy of the object.

is the mass of the object.

is the speed of the object.
We know form our problem that the mass of the horse is 500 kilograms, so

; we also know that the speed of the horse is 5 meter/second, so

. Lets replace those values in our formula to find

:





J
We can conclude that the kinetic energy of the horse is
6250 Joules.