Answer:
I believe the answer is D
Explanation: The doppler affect isan increase or decrease in the frequency of sound, light, or other waves as the source and observer move toward or away from each other.
Answer:
Option c is correct
Explanation:
There are two types of collisions-elastic collision and inelastic collision.
In elastic collision, both kinetic energy and total momentum are conserved. On the other hand, in inelastic collision, total momentum is conserved but kinetic energy is not conserved. Thus, option b and d are incorrect.
Total energy is always conserved in both types. Thus, option a is incorrect.
In a perfectly inelastic collision, objects stick together. This happens because maximum kinetic energy is dissipated and used in bonding of the two objects. Thus, correct option is c.
Answer:
A=
Explanation:
We have given power =40 W but only 10% of this power is used so actual power 
We know that from Stefan's law 
where 
is Boltzmann constant which value is 
So 
A=
Answer:
Have a quick snack an hour before to get the energy, warm up
