K.E=0.5*mv²
v=square root 2ke/m
v= square root 2*8J/1 kg
v= 4 m/s
<h2>
<u>KINETIC ENERGY</u></h2>
<h3>Problem:</h3>
» A 2kg mass is moving at 3m/s. What is its kinetic energy?
<h3>Answer:</h3>
— — — — — — — — — —
<h3>Formula:</h3>
To calculate the velocity of a kinetic energy, we can use formula
where,
- v is the velocity in m/s
- KE is the kinetic energy in J (joules)
- m is the mass in kg
— — —
Based on the problem, the givens are:
- KE (Kinetic energy) = ? (unknown)
- m (mass) = 2 kg
- v (velocity) = 3 m/s
<h3>Solution:</h3>
To get the velocity, substitute the givens in the formula above then solve.

Therefore, the kinetic energy is 9 Joules.
Answer: 0.43 V
Explanation:
L = [μ(0) * N² * A] / l
Where
L = Inductance of the solenoid
N = the number of turns in the solenoid
A = cross sectional area of the solenoid
l = length of the solenoid
7.3*10^-3 = [4π*10^-7 * 450² * A] / 0.24
1.752*10^-3 = 4π*10^-7 * 202500 * A
1.752*10^-3 = 0.255 * A
A = 1.752*10^-3 / 0.255
A = 0.00687 m²
A = 6.87*10^-3 m²
emf = -N(ΔΦ/Δt).........1
L = N(ΔΦ/ΔI) so that,
N*ΔΦ = ΔI*L
Substituting this in eqn 1, we have
emf = - ΔI*L / Δt
emf = - [(0 - 3.2) * 7.3*10^-3] / 55*10^-3
emf = 0.0234 / 0.055
emf = 0.43 V