Answer:
final kinetic energy of the hammer is 10 kJ
Explanation:
As we know that there is no non conservative force on the system
So here we can use the theory of mechanical energy conservation
So we will have

here we know that

from above expression now


so final kinetic energy of the hammer is 10 kJ
Answer: 20 m/s
Explanation: To solve this problem we have to consider the expression of the kinetic energy given by:
Ekinetic=(1/2)*(m*v^2)
then E=0.5*30Kg*(20 m/s)^2=15*400=6000J
If you decrease the pressure of a fixed amount of gas, its volume will increase.
ANOTHER RUNNING DOG
Explanation:
In the given question it is to find a suitable reference point to describe the motion of dog. Here I could suggest that it is better to compare the dog with another running dog to create the relative speed difference to get a reliable motion variation.
Because the motion of dog is in the linear with respect to the another dog and to the acceleration produced by the dog in the required interval is easy to calculate with respect to another dog which is already in motion.
Hence, I suggest that Motion of dog can be analysed better by analyse the motion variation of dog with another dog running.
Answer:
Decreases.
Explanation:
The rise in temperature of gas increases the kinetic energy of its molecules and they rush out of water instead of dissolving similarly as air rushes out of boiling water in form of bubbles