Answer:
After throwing the object the, the velocity of the man is 13.98 m/s
Explanation:
Given:
Let,
mass of man, m1 = 74 kg
mass of box, m2 = 13 kg
Initial velocity u = 11 m/s (initially both are together hence initial velocity will be same for both)
Final velocity of man = v1
Final velocity of box = v2 = -6 m/s (the velocity is recoil velocity therefore it is negative)
To Find:
Final velocity of man,after throwing the object = v1 = ?
Solution:
Recoil velocity:
It is the backward velocity experienced.
Here recoil velocity is the backward velocity experience while throwing the box behind.Hence the velocity of the box is negative 6 m/s.
The recoil velocity is the result of conservation of linear momentum of the system. Therefore we will follow the law of conservation of momentum.
Law of conservation of momentum :
Total momentum of an isolated system before collision is always equal to total momentum after collision

substituting the values which are given above we get

Therefore, After throwing the object the, the velocity of the man is 13.98 m/s
Answer:
Induced emf in the coil,
Explanation:
Given that.
Number of turns in the coil, N = 200
Side of square, d = 18 cm = 0.18 m
The field changes linearly from 0 to 0.50 T in 0.80 s.
To find,
The magnitude of the induced emf in the coil while the field is changing.
Solution,
We know that due to change in the magnetic field, an emf gets induced in the coil. The formula of induced emf is given by :
= magnetic flux
A is the ares of square
So, the induced emf in the coil is 4.05 volts. Hence, this is the required solution.
Forget about the car's speed. You don't need it.
The tires spin 840 rpm. That's 840 <em>Revolutions per Minute</em> .
There are 60 seconds in 1 minute. So something that happens 840 times in 1 minute happens (840 / 60) times every second.
(840 rev per minute) / (60) = <em>14 revs per second</em> .
They seem to cancel each other out which is odd