The Doppler effect is the change in sound or light that occurs whenever there is motion between the source and its observer. The siren of the fire engine has a lower pitch as it moves away because the waves are now spread out causing a lower frequency and a lower pitch. High-frequency sound waves have a higher pitch and higher energy than low-frequency waves.
Answer:
By the order its placed in
Explanation:
"<em>F = dP/dt. </em> The net force acting on an object is equal to the rate at which its momentum changes."
These days, we break up "the rate at which momentum changes" into its units, and then re-combine them in a slightly different way. So the way WE express and use the 2nd law of motion is
"<em>F = m·A.</em> The net force on an object is equal to the product of the object's mass and its acceleration."
The two statements say exactly the same thing. You can take either one and work out the other one from it, just by working with the units.
Explanation:
In washing machine, the electrical energy is converted in kinetic energy then the mechanical energy is converted into thermal (heat) energy.
Answer:
at R/
Explanation:
The free-fall acceleration at the surface of Earth is given by
where
G is the gravitational constant
M is the Earth's mass
R is the Earth's radius
The formula can be rewritten as
(1)
We want to shrink the Earth at a radius R' such that the acceleration of gravity becomes 3 times the present value, so
g' = 3g
Keeping the mass constant, M, and substituting into the equation, we have
