This question deals with the law of conservation of momentum, which basically says that the total momentum in a system must stay the same, provided there are no outside forces. Since you were given the mass and velocity of the two objects you can find the momentum (p=mv) of each and then add them together to find the total momentum of the system before they collide. This total momentum must be the same after they collide. Since you have the mass and velocity of one of the objects after the collision you can find the its momentum after. Subtract this from the the system total and you will have the momentum of the other object after the collision. Now that you know the momentum of the other object you can find its velocity using p=mv and its mass from before.
Be careful with the velocities. They are vectors, so direction matters. Typically moving to the right is positive (+) and moving to the left is negative (-). It is not clear from your question which direction the objects are moving before and after the collision.
The Young modulus is given by:

where
F is the force applied

is the initial length of the wire

is the cross-sectional area of the wire

is the stretch of the wire
The wire in the problem stretches by

of its length, this means

We can also calculate the area of the wire; its radius is in fact half the diameter:

and so the area is

We know the force applied to the wire, F=20 N, so now we have everything to calculate the Young modulus:
Answer:
Density of body = 0.25g/cc
Explanation:
Given:
Volume submerged in water = 3/4
Find:
Density Of Body
Computation:
Density of body = fraction of body in liquid x density of water
Density of body = [1-3/4]1
Density of body = 0.25g/cc
Answer:

Explanation:
given data:
flow Q = 9 m^{3}/s
velocity = 8 m/s
density of air = 1.18 kg/m^{3}
minimum power required to supplied to the fan is equal to the POWER POTENTIAL of the kinetic energy and it is given as

here
is mass flow rate and given as


Putting all value to get minimum power


Answer:

Explanation:
The speed of light is given by
and
hence

Speed of light is given by
