The kinetic energy with which the hammer strikes the ground
is exactly the potential energy it had at the height from which it fell.
Potential energy is (mass) x (gravity) x (height) .... directly proportional
to height.
Starting from double the height, it starts with double the potential
energy, and it reaches the bottom with double the kinetic energy.
The answer is A
Materials that are good conductors of thermal energy are called thermal conductors. Metals are very good thermal conductors. Materials that are poor conductors of thermal energy are called thermal insulators. Gases such as air and materials such as plastic and wood are thermal insulators
Answer:
B) The cosmic background radiation is expected to contain spectral lines of hydrogen and helium, and it does.
Explanation:
Answer:
T = 692.42 N
Explanation:
Given that,
Mass of hammer, m = 8.71 kg
Length of the chain to which an athlete whirls the hammer, r = 1.5 m
The angular sped of the hammer, 
We need to find the tension in the chain. The tension acting in the chain is balanced by the required centripetal force. It is given by the formula as follows :
So, the tension in the chain is 692.42 N.
