Answer:
Friction force is the force that one object exerts in another when the two rub against each other. Most of the time, friction force opposes the motion of an object.
Explanation:
Two or more velocities add by vector addition
The wavelength of the note is
. Since the speed of the wave is the speed of sound,
, the frequency of the note is
Then, we know that the frequency of a vibrating string is related to the tension T of the string and its length L by
where
is the linear mass density of our string.
Using the value of the tension, T=160 N, and the frequency we just found, we can calculate the length of the string, L:
A firecracker before been lit has potential energy in it. It is chemical potential energy which is due to the explosives in it.When it is lit, it gets converted into heat,light and kinetic energy.