Refraction is the change in direction of a wave, caused by the change in the wave's speed. Examples of waves include sound waves and light waves. Refraction is seen most often when a wave passes from one transparent medium to another transparent medium. Different types of medium include air and water. When a wave passes from one transparent medium to another transparent medium, the wave will change its speed and its direction. For example, when a light wave travels through air and then passes into water, the wave will slow and change direction.
Answer: B - 8
Explanation: 8 protons because number of protons is equal to number of atoms in the nucleus.
Answer:
A. potential energy is 258720 Joule
Explanation:
A.Gravitational potential energy is: PE = m × g × h
velocity = 15.33 m/s when the car reaches the bottom of the hill.
where, m = mass
g = acceleration due to gravity
h = height from the bottom of hill.
The potential energy is : m×g×h
=(2200×9.8×12)
=258720 Joule
B. at the bottom of the hill, the potential energy is converted into kinetic energy so PE at top = KE at bottom
kinetic energy=
(
)
where v = velocity
m= mass
therefore, v=
or, v=
or, v=15.33 m/s