Answer:
10880N
Explanation:
We are given that
Mass of elevator, m=850 kg
Acceleration, 
We have to find the tension in the cable.
We know that
When elevator is accelerating upward then tension in the cable
Using the formula
Increasing the masses of the objects and decreasing the distance between the objects
Answer:
39200 joules
the potential energy will be zero
Explanation:
we know that potential energy is found by multiplying mass, acceleration due to gravity and height from the Earth's surface
so it will be
potential energy= mgh
80x9.8x15
= 39200 joules
the potential energy of the mental ball will be zero when kept on the Earth's surface because the height from the Earth's surface will be zero and zero multiplied to any number is zero only
I have a doubt with the second one, this is what I think it is. Consult your teacher if you think my answer for the second one is wrong
