Answer:
gravitational force is a fundamental force and also , it does have a small range and is always an attractive force.
Explanation:
B) 14.0 N
The way to solve this problem is to determine the kinetic energy the box had before and after the rough patch of floor. The equation for kinetic energy is:
E = 0.5 M V^2
where
E = Energy
M = Mass
V = velocity
Substituting the known values, let's calculate the before and after energy.
Before:
E = 0.5 M V^2
E = 0.5 13.5kg (2.25 m/s)^2
E = 6.75 kg 5.0625 m^2/s^2
E = 34.17188 kg*m^2/s^2 = 34.17188 joules
After:
E = 0.5 M V^2
E = 0.5 13.5kg (1.2 m/s)^2
E = 6.75 kg 1.44 m^2/s^2
E = 9.72 kg*m^2/s^2 = 9.72 Joules
So the box lost 34.17188 J - 9.72 J = 24.451875 J of energy over a distance of 1.75 meters. Let's calculate the loss per meter by dividing the loss by the distance.
24.451875 J / 1.75 m = 13.9725 J/m = 13.9725 N
Rounding to 1 decimal place gives 14.0 N which matches option "B".
Hey,
Storage of energy is known as potential energy. If you take a spring for example, and you stretch it then you hold it, it has the energy you put into it but it is potential since it's not moving. Of course once you let go of it its potential energy turns into kinetic energy.
There are other examples as well, such as a battery. I decided to use the spring example because it is simpler.
I hope it helped.
I wrote all that^.
