Answer:
45.31 J
Explanation:
We are given that
Mass of baseball , m=0.145 kg
Initial velocity, u=0
Final velocity, v=25 m/s
We have to find the work done on the baseball to bring it from rest to 25 m/s
We know that
Work done = Change in kinetic energy
Work done, W=
Using the formula
Work done, W
Work done=
Work done, W=45.31 J
Hence, the work done on the baseball to bring it from rest to 25 m/s
=45.31 J
1.
The total energy given to the cells during one pulse is given by:
where
P is the average power of the pulse
t is the duration of the pulse
In this problem,
Substituting,
2.
The energy found at point (1) is the energy delivered to 100 cells. The radius of each cell is
So the area of each cell is
The energy is spread over 100 cells, so the total area of the cells is
And so the intensity delivered is
3.
The average intensity of an electromagnetic wave is related to the maximum value of the electric field by
where
c is the speed of light
is the vacuum permittivity
E is the amplitude of the electric field
Solving the formula for E, we find:
4. 3247 T
The magnetic field amplitude is related to the electric field amplitude by
where
E is the electric field amplitude
c is the speed of light
B is the magnetic field
Solving the equation for B and substituting the value of E that we found at point 3, we find