Answer:
Change in potential energy = 7350 Joules
Explanation:
It is given that,
Side of cube, a = 0.5 m
Density of cube, 
The cube is lifted vertically by a crane to a height of 3 m
We know that, density 
So, m = d × V (V = volume of cube = a³)

m = 250 kg
We have to find the change in potential energy of the cube. At ground level, the potential energy is equal to 0.
Potential energy at height h is given by :

PE = 250 kg × 9.8 m/s² ×3 m
PE = 7350 Joules
So, change in potential energy of the cube is 7350 Joules.
Answer:

Explanation:
From the question we are told that:
Pressure of 
Bottle cap area 
Generally the equation for Resultant pressure
is give as is mathematically given by

Where



Generally the equation for Force exerted by screw F is give as is mathematically given by


Answer:
Negative
Explanation:
If the box is heading right in the positive direction, the work will be negative. The spring has an opposite force to that of the box.
Hope this helped. :)
. In single particle problem whole mass is concentrated at a single point so it has a single displacement, single velocity and single acceleration. while, in rigid body mass is distributed
Answer:
The power will be "3.92×10⁹ Watts". A further explanation is given below.
Explanation:
The given values as per the question,
Rate,
= 8 million kg
Distance,
= 50 m
Gravity,
= 9.8 m/s²
As we know,
The power will be:
⇒ 
On putting the values, we get
⇒ 
⇒ 