Answer:
21.53 x 10^{6} N
Explanation:
force (F) = 4.71 x 10^{3} N
distance (s) = 4.57 km = 4570 m
how much work is done.
work = force x distance
work = 4.71 x 10^{3} x 4570 = 21.53 x 10^{6} N
Answer:
When Momentum is conserved it is called conservation of momentum
Explanation:
Answer: True
Explanation: Hope this helps :)
Answer:
Explanation:
The energy of a photon is given by the equation 
, where h is the <em>Planck constant</em> and f the frequency of the photon. Thus, N photons of frequency f will give an energy of 
.
We also know that frequency and wavelength are related by 
, so we have 
, where c is the <em>speed of light</em>.
We will want the number of photons, so we can write
We need to know then how much energy do we have to calculate N. The equation of power is 
, so for the power we have and considering 1 second we can calculate the total energy, and then only consider the 4% of it which will produce light, or better said, the N photons, which means it will be 
.
Putting this paragraph in equations:
.
And then we can substitute everything in our equation for number of photons, in S.I. and getting the values of constants from tables:
