Answer:
Push with force of 1N
Explanation:
I have explained in the paper.
Goodluck
Answer:
emf will also be 10 times less as compared to when it has fallen 
Explanation:
We know, from faraday's law-

and 
So, as the height increases the velocity with which it will cross the ring will also increase. 
Given


Now, from 

From equation a and b we see that velocity when dropped from
is 10 times greater when height is 40
so, emf will also be 10 times less as compared to when it has fallen 
Complete question:
A college dormitory room measures 14 ft wide by 13 ft long by 6 ft high. Weight density of air is 0.07 lbs/ft3. What is the weight of air in it under normal conditions?
Answer:
the weight of the air is 76.44 lbs
Explanation:
Given;
dimension of the dormitory, = 14 ft by 13 ft by 6 ft
density of the air, = 0.07 lbs/ft³
The volume of the air in the dormitory room = 14 ft x 13 ft x 6 ft
= 1092 ft³
The weight of the air = density x volume
= 0.07 lbs/ft³ x 1092 ft³
= 76.44 lbs
Therefore, the weight of the air is 76.44 lbs
Answer:

Explanation:
- We have to make a hollow sphere of inner radius
and outer radius
.
Then the mass of the material required to make such a sphere would be calculated as:
Total volume of the spherical shell:

And the volume of the hollow space in the sphere:

Therefore the net volume of material required to make the sphere:


- Now let the density of the of the material be
.
<u>Then the mass of the material used is:</u>


Answer:
3.117 m
Explanation:
Given that:
the distance of separation between speaker A and speaker B (L) = 6.69 m
Frequency (F) = 750 -Hz tone
Velocity of speed of sound = 343 m/s
The distance from Speaker A to the first point (L₁) on the line can be calculated by using the formula:

where A = 
we have:






∴ the distance from speaker A to the first point on the line between the speakers where constructive interference occurs = 3.117 m