Answer:
14009. 72 kgms^-1
Explanation:
Momentum is the product of an objects mass and velocity
The correct answer is A.
The coefficient of absorption of material A is 30%. So, the material will absorb 30% energy of the incident wave falling on it. Thus, the reflected wave will carry the rest 70% energy.
The coefficient of absorption of material B is 47%. So, the material will absorb 47% energy of the incident wave falling on it. Thus, the reflected wave will carry the rest 53% energy.
The coefficient of absorption of material C is 62%. So, the material will absorb 62% energy of the incident wave falling on it. Thus, the reflected wave will carry the rest 28% energy.
Hence, material C would be the best, because the percentage of the energy in an incident wave that remains in a reflected wave from this material is the smallest.
Neutral charge, because neutron means neutral
The mistake here is that the total energy of the system does not change - generally, the total amount of energy in a system never changes unless the energy enters or leaves the system somehow (for example, if you see the Earth alone as a system, then energy from the sun enters the system and some energy is lost to space in the form of heat).
Mass of the system is 25.2 kg
Calculation:
F=ma
m = F/a where a = m/t^2
a=2.3/(1.3)^2 = 1.36 m/s^2
m=34.3/1.36
m=25.2 Kg
