Hello!
We can use the following equation for calculating power dissipated by a resistor:

P = Power (? W)
i = Current through resistor (2.0 A)
R = Resistance of resistor (50Ω)
Plug in the known values and solve.

Answer:
B'=1.935 T
Explanation:
Given that
magnetic field ,B= 0.645 T
We know that magnetic filed in the solenoid is given as

I=Current
n=Number of turn per unit length
μ0 =magnetic permeability
Now when the current increased by 3 factors
I'=3 I
Then the magnetic filed


B'=3 B
That is why
B' = 3 x 0.645 T
B'=1.935 T
Therefore the new magnetic filed will be 1.935 T.
Answer: a= 52.02 m/s²
Fc= 78.03 N
Explanation: Solution attached:
It is the very last answer