Answer;
= 4 m is the length of the man's shadow.
Explanation;
2/x=6/(8+x) cross multiply.
6x=2(8+x)
6x=16+2x
6x-2x=16
4x=16
x=2=16/4
x=4 m. is the length of the man's shadow.
The acceleration due to gravity on Earth is 9.8 m/s per second.
Answer:
P = 14700 J
Explanation:
Given that,
Mass of a piano, m = 75 kg
It is delivered throughout the window of a 6th story apartment which is 20 m above the ground.
We need to find the potential energy of the piano. It is given by :
P = mgh
Putting all the values,
P = 75 kg × 9.8 m/s² × 20 m
P = 14700 J
So, the potential energy of the piano is 14700 J.
B) gravitational to kinetic
Explanation:
The skydiver, when he is located at a certain height h above the ground, possesses gravitational potential energy, equal to:

where m is the mass of the skydiver, g is the gravitational acceleration and h is the height above the ground. As he falls, its height h decreases, while his speed v increases, so part of the gravitational potential energy is converted into kinetic energy, which is given by

so, we see that as v increases, the kinetic energy increases. Therefore the correct answer is
B) gravitational to kinetic
Answer:
is always negative
Explanation:
Air resistance is a non-conservative force it opposes the motion of an object.It is a force that is always directed opposite to the displacement.