..............................................A
Answer:
Final angular velocity is 35rpm
Explanation:
Angular velocity is given by the equation:
I1w1i + I2w2i = I1w1f -I2w2f
But the two disks are identical, so Ii =I2
wf can be calculated using
wf = w1i - w2i/2
Given: w1i =50rpm w2i= 30rpm
wf= (50 + 20) / 2
wf= 70/2 = 35rpm
Answer
given,
Length of the string, L = 2 m
speed of the wave , v = 50 m/s
string is stretched between two string
For the waves the nodes must be between the strings
the wavelength is given by

where n is the number of antinodes; n = 1,2,3,...
the frequency expression is given by

now, wavelength calculation
n = 1

λ₁ = 4 m
n = 2

λ₂ = 2 m
n =3

λ₃ = 1.333 m
now, frequency calculation
n = 1


f₁ = 12.5 Hz
n = 2


f₂= 25 Hz
n = 3


f₃ = 37.5 Hz
Correct Question:-
A jack exerts a vertical force of 4.5 × 10³
newtons to raise a car 0.25 meter. How much
work is done by the jack?

Given :-



To find:-


Solution:-
we know :-


So:-



























-- Kinetic energy is the energy of mass in motion. The amount is determined by the mass of whatever is moving, and its speed.
-- Potential energy is the energy that's stored up in some form, not being used yet but ready to be used when you want it.
For example, one form of it is <u><em>chemical</em></u><em> </em>potential energy, like in a battery, or a match. You get the energy out of a battery when you connect it to a motor or a light. You get the energy out of as match when you make the tip hot and it flares up.
This question is asking about <u><em>gravitational</em></u> potential energy. An object has stored energy just by being up high, like a bowling ball on a shelf. You get the energy out of it just by dropping it ... possibly enough to crack the floor !
The amount of this kind of potential energy is determined by the mass of the object, and how high up it is.
-- Getting the answers from other people doesn't help you a bit, until you understand them and can answer the question on your own.