Answer:
Explanation:
magnetic filed, B = 0.65 T
initial diameter, d = 17.5 cm
final diameter, d' = 6.6 cm
time, t = 0.48 s
(a) According to Lenz's law, the direction of induced current is clockwise.
(b) Let e is the induced emf.
initial area, A = π r² = 3.14 x 0.0875 x 0.0875 = 0.024 m²
final area, A' = π r'² = 3.14 x 0.033 x 0.033 = 0.00342 m²
change in area, ΔA = A - A' = 0.024 - 0.00342 = 0.02058 m²
The magnitude of induced emf is given by


e = 0.65 x 0.02058 / 0.48
e = 0.028 V
(c) R = 2.5 ohm
i = e / R
i = 0.028 / 2.5
i = 0.011 A
Answer:

Explanation:
Given


Required
Determine the object's speed
Kinetic Energy is calculated as:

Make m the subject

Momentum is calculated as:

Make m the subject

So, we have:
and 
Equate both expressions: 

Multiply both sides by v


Make v the subject

Substitute
and 



A billiard ball moves with 3 kg⋅m/s of momentum and strikes three other billiard balls that have been just sitting there at rest and not moving.
The total momentum of all four balls after the collision is <em>3 kg⋅m/s</em>, because momentum is not created or destroyed. The total amount of it after an event is the same as the total amount of it before the event.