Answer:
(a) The magnetic energy density in the field is 6.366 J/m³
(b) The energy stored in the magnetic field within the solenoid is 5 kJ
Explanation:
magnitude of magnetic field inside solenoid, B = 4 T
inner diameter of solenoid, d = 6.2 cm
inner radius of the solenoid, r = 3.1 cm = 0.031 m
length of solenoid, L = 26 cm = 0.26 m
(a) The magnetic energy density in the field is given by;

(b) The energy stored in the magnetic field within the solenoid


Answer: 288 m
Explanation: 288 m is the correct answer because the question states that the ball is thrown at 96 m every second, and our question tells us that the ball travels 3 seconds. This means we have to multiply 96 x 3 = 288 m.