C) light waves travel faster than sound waves
You were correct
A supernova is a star that suddenly increases greatly in brightness because of a catastrophic explosion that ejects most of its mass.
Answer:
B: Amplitude
Explanation:
When a wave travels from one medium to the other from an angle, the things that change are amplitude, wavelength, intensity and velocity.
The frequency doesn't change because the frequency depends upon the source of the wave and not the medium by which the wave is propagated.
Answer:
B
Explanation:
hair can be a safety hazard
Answer:
Part a)

Part b)

Part c)

Explanation:
As we know that 5000 kg African elephant requires 70,000 Cal for basic needs per day
so we will have


so we have energy required per kg


Part a)
now we know that per kg the energy required will be same
so we have mass of the human is 68 kg
so energy required per day is given as


Part b)
Resting power is the rate of energy in Joule required per sec
so it is given as


Part c)
resting power given in the book is

so this is less than the power given

