The study of EM is essential to understanding the properties of light, its propagation through tissue, scattering and absorption effects, and changes in the state of polarization. ... Since light travels much faster than sound, detection of the reflected EM radiation is performed with interferometry.
Answer:
F = 768 N
Explanation:
It is given that,
Speed of the elevator, v = 3.2 m/s
Grain drops into the car at the rate of 240 kg/min, 
We need to find the magnitude of force needed to keep the car moving constant speed. The relation between the momentum and the force is given by :


Since, the speed is constant,



F = 768 N
So, the magnitude of force need to keep the car is 768 N. Hence, this is the required solution.
Answer:
4000J
Explanation:
Given parameters:
Weight of the man = 800N
Height of ladder = 5m
Unknown:
Gravitational potential energy gained = ?
Solution:
The gravitational potential energy is due to the position of a body.
Gravitational potential energy = weight x height
Now insert the parameters;
Gravitational potential energy = 800 x 5 = 4000J