Answer:

Explanation:
The energy of a photon is:
when h is the Planck constant.

Then, we calculate the energy of a photon with a wavelength equal to 550 nm.

To find the number of photons we can use this equation:

Have a nice day!
You need distance and time to find average speed.
Answer:
t=444.4s
Explanation:
m=1.5*10^7 kg
F=7.5*10^5 N
v=80km/h*(1h/3600s)*(1000m/1km)=22.22m/s
<u>Second Newton's Law:</u>
F=ma
a=F/m=7.5*10^5/(1.5*10^7)=0.05m/s^2
<u>Kinematics equation:</u>
vf=vo+at=at
vo: initial velocity equal zero
t=vf/a=22.22/0.05=444.4s
Answer:
vx = 65 yd/3 sec = 21.7 yd/sec since horizontal speed is constant
vy = g t = (32 / 3) yd/sec^2 * 1.5 sec = 16 yd/sec where 32/3 is the acceleration due to gravity in yds / sec^2 and 1.5 is the time to travel each way in the vertical direction
V = (vx^2 + vy^2)^1/2 = (21.7^2 + 16^2)^1/2 = 27 yd/sec
tan theta = vy/vx = 16 / 21.7 = .737 theta = 36.4 deg
You can check using the range formula:
R = v^2 sin (2 theta) / g = 27^2 * .955 / (32 / 3) = 65.3 yds
The difference from 65 yds may be rounding error.