Answer:

Explanation:
Given,
Magnetic field, B = 5 x 10⁻⁵ T
Number of turns, N = 450
length = 29 cm
Current,I = ?
Using formula of magnetic field due to solenoid




Hence, the current obtained is equal to 0.0256 A.
The Potential energy stored in the system is 1 J
<u>Explanation:</u>
Given-
Mass, m = 4 kg
Spring constant, k = 800 N/m
Distance, x = 5cm = 0.05m
Potential energy, U = ?
We know,
Change in potential energy is equal to the work done.
So,

By plugging in the values we get,

Therefore, Potential energy stored in the system is 1 J
Answer by mimiwhatsup: B) Velocity is a vector and requires a direction to completely describe it.
Velocity is the speed and direction of an object in motion.