Answer
Calculate the amount of heat needed to melt 2.00 kg of iron at its melting point (1809 K), given that: ?Hfus = 13.80
Answer:b
Explanation:
Given
mass of first cart 
mass of second cart 
velocity of first cart 
conserving momentum



Initial kinetic Energy 


Final Kinetic Energy


Ratio of initial Kinetic Energy to the Final Kinetic Energy

Answer:
50 W
Explanation:
<h3>
<u>Given :</u></h3>
- Force applied = 100 N
- Distance covered = 5 metres
- Time = 10 seconds
<h3>
<u>To find :</u></h3>
Power
<h3>
<u>Solution :</u></h3>
For calculating power, we first need to know about the work done.

Now, substituting values in the above formula;
Work = 100 × 5
= 500 Nm or 500 J
We know that,

Substituting values in above formula;
Power = 500/ 10
= 50 Nm/s or 50 W
Hence, power = 50 W .