If you study a week before you should memorize & study the night & day of
The power of the laser is

by using the relationship between power, energy and time, we can find the energy delivered by the laser in 1 second:

The frequency of the photons of this light is given by

and the energy of a single photon is

In order to find the number of photons emitted per second, we must divide the total energy emitted by the laser by the energy of a single photon, and we get:
Answer:
35%
Explanation:
Given data
Amount of energy transferred (Input) = 270J
Amount of energy converted to sound (Output)= 94.5J
Efficiency = output/input*100
Efficiency= 94.5/270*100
Efficiency=0.35*100
Efficiency=35%
Hence the efficiency is 35%
4 times as much distance to stop
Answer:
∑Fy = 0, because there is no movement, N = m*g*cos (omega)
Explanation:
We can solve this problem with the help of a free body diagram where we show the respective forces in each one of the axes, y & x. The free-body diagram and the equations are in the image attached.
If the product of mass by acceleration is zero, we must clear the normal force of the equation obtained. The acceleration is equal to zero because there is no movement on the Y-axis.