Answer:
Explanation:
Refractive Index: It is a measure to find how fast the light travels through a medium. It is ration of the speed of light in vacuum to speed of light in the medium. Speed of light is not constant and varies depending on the density of the medium.
In vacuum the speed of light is 300000 km/s and is denoted by c. When the light beam enters any medium the speed will decrease. Here it is given that the speed in plastic is v. Thus the refractive index(n) is given as:
It is a dimensionless no.
Question 18: a
question 19: b
question 20: c
Red shirt appears red because:
a. The shirt reflects red light
The only function of the pulleys in the diagram is to change the direction
of the force applied to raise the bricks.
<h3>What is a Pulley?</h3>
A pulley is a wheel which has a flexible rope on its rim and helps to
transmit energy and motion.
In the diagram given, we can see that the pulley is used to raise a mass of
block by three people. They pull the rope horizontally in order to raise the
block vertically. This means that it was used to change the direction of the
applied force.
Read more about Pulley here brainly.com/question/177456
Answer:
True, the total amount of mechanical energy is merely the sum of the potential energy and the kinetic energy. This sum is simply referred to as the total mechanical energy.
Explanation: Hope it helps you:))))
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