Answer:
The answer is given below
Explanation:
u is the initial velocity, v is the final velocity. Given that:

a)
The final velocity of cart 1 after collision is given as:

The final velocity of cart 2 after collision is given as:

b) Using the law of conservation of energy:

A. Solid turns into a gas
Tom used more Force but over a shorter distance. Tom and Claudia both did the same amount of work.
Answer:
0.80 c
Explanation:
The computation of speed is shown below:-
Here, The speed of the captain ship A report for speed of the ship B which is

where
indicates the speed of the ship A
indicates the speed of the ship B
and
C indicates the velocity of life
now we will Substitute 0.40c for A and 0.60 for B in the equation which is

after solving the above equation we will get
0.80 c
So, The correct answer is 0.80c