Answer:
The final energy of the system is 168 J
Explanation:
Heat energy released to the surroundings, 
Work done, W = 222 J
The initial internal energy, 
The change in internal energy is given by the formula, 
The final energy of the system is 168 J
The Mechanical Energy is given by the sum of the all energies of the system.
Answer:
Explanation:
Assuming that cars 4 and 5 have same mass so that the momentum
P=mv where m is mass and v is velocity hence
Momentum=0+2mv+3mv=5mv
The final mass is 2m+3m=5m
From aw of conservation of momentum
hence 
Therefore, the speed is
Answer:
The speed is the same as long as the reflection is regular.
Explanation:
This is because in regular reflection, the angle of incidence is equal to the angle of reflection in accordance with the second law of reflection.
Since speed of light depends on the angle of the light ray it makes with the reflecting surface, the speed is the same
