Hello, i really need with these 4 questions. they are both physical science combined with mathematics. i am giving out brainliest, and 50 points for whoever is an emergency and i would appreciate it.

1) We know, W = F * s
w = 30 * 15
w = 450 Joules

Now, Power = work done / Time taken 
p = 450 / 8
p = 56.25 Watts

2) When ball lifts from bottom to the top, it's P.E. will rise to the top and it will be greatest at the top point, whereas K.E. will decrease during the rise, and it will be lowest at the highest point, and will be maximum at the bottom point, when potential energy will be zero

3) On the Top, you have highest potential energy as it is directly proportional to the height of the object/person, and for bottom, it will be zero whereas Kinetic Energy will be maximum as sum of their magnitude must be constant at each instances (According to Law of Conservation of Energy).
Friction will decrease the amount of Energy by some extent due to it's opposing nature

4) Potential Energy (Initial one) = m * g * h
= 25 * 9.8 * 4 = 980 J

Kinetic Energy = 1/2 mv² 
= 1/2 * 25 * 5² = 312.5 J

Energy lost  = Final - Initial = 980 - 312.5 = 667.5 Joules

Hope this helps!

Work=Force times distance
Work= 30×15
Work=450
So you did 450J of work

The best answer is (a) which is universal law is in effect at all times. it is constantly at play in everything we do and governs our lives. it is also important to note that universal law applies to not only everything on earth, but everything in the universe as well, which is another reason why it is in effect at all times.