Answer:
<h2>
D.)</h2>
Explanation:
Potential energy is when a object is not in motion and the ball is sitting on a shelf not being thrown around or rolling. kinetic energy is when a obeject is in motion and moving.
Stars having less mass collapses early than those with more mass. This can be explained by Einstein's equation E=mc².
According to this equation, mass of stars is converted into light due to thermonuclear reactions occuring in the core of star which acts as engine of the stars. This thermonuclear reactions keeps star alive. Thermonuclear reactions occurs slowly in massive stars hence massive stars live more than light stars.
Refraction is said to occur when there is a change in the speed of light.
<h3>What is the angle of refraction?</h3>
We know that refraction is said to occur when there is a change in the speed of light as it travels form one medium to another.
Given that the refractive index of the rectangular glass block is 1.5. The angle of refraction can be obtained by the use of the Snell's law;
n = sin i /sinr
n = refractive index
sini = angle of incidence
sin r = angle of refraction
sinr = sini/n
sinr = sin 45/1.5
= 0.471
r = 28 degrees
b) Now;
sinr =sin 45/1.2
sinr = 0.589
r = 36 degrees
For the glass
sinr = sin 36/1.5
sin r = 0.392
r = 23 degrees
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Answer:
Explanation:distance-time =speed
a,V =s/t
V=2m/2s
V=1m/s
b,v=s/t
V=80m/40s
V= 2m/s
The average speed is 2m/s
