Answer:
The height at which the object is moved is 10 meters.
Explanation:
Given that,
Force acting on the object, W = F = 490 N
The gravitational potential energy, P = 4900 J
We need to find the height at which the object is moved. We know that the gravitational potential energy is possessed due to its position. It is given by :

So, the height at which the object is moved is 10 meters. Hence, this is the required solution.
Please check the attached picture
Explanation:
formula for energy is k. e = ½mv²
m= 9
v= 75
k. e = ½×9×75 =337•5
The answer is B.
This is because you add up all of the times (1.44s+1.70s+1.58s+1.76s) and you get 6.48 then you divide 6.48 by 4 to get the average of the times. Now you get the distance (200m) and because speed=distance/time you divide 200m/1.62s to get 123m/s. I hope this made sense :)