Answer:
The actual elevation angle is 12.87 degrees
Explanation:
In the attachment you can clearly see the situation. The angle of elevation as seen for the scuba diver is shown in magenta, we conclude that
.
Using Snell's Law we can write:

,
Let's approximate the index of refraction of the air (medium 1 in the picture) to 1.
We thus have:

. Calling
the actual angle of elevation, we get from the picture that
Answer:
Lead, Ethyl alcohol and water.
Explanation:
Specific heat capacity of a substance can be define as the quantity of heat that is absorbed by a substance needed to change the temperature of a unit mass of one kilogram of the substance by one kelvin
Answer:
Net force will be 4.875 N
Explanation:
We have given mass of the cart m = 1.5 kg
Initial velocity of the cart = 0.2 m/sec
And final velocity of the car = - 0.125 m/sec ( Negative direction is due to opposite direction )
Instant of time 
Change in momentum is given by

Now force is given by

Net force will be 4.875 N