When the wire is twice as long. Also when the cross sectional area is halved
Answer:
- 144 V
Explanation:
A = (2, 3) m = 2 i + 3 j
B = (5, 7) m = 5 i + 7 j
Displacement vector = AB = B - A = (3 i + 4 j) m
Electric field, E = (4 i + 3 j ) N/C
V = - E . AB
V = - (4 i + 3 j) . (3 i + 4 j)
V = - (12 + 12) = - 144 V
Explanation:
It is given that,
Mass of the ball, m = 0.06 kg
Initial speed of the ball, u = 50.4 m/s
Final speed of the ball, v = -37 m/s (As it returns)
(a) Let J is the magnitude of the impulse delivered to the ball by the racket. It can be calculated as the change in momentum as :

J = -5.24 kg-m/s
(b) Let W is the work done by the racket on the ball. It can be calculated as the change in kinetic energy of the object.


W = -35.1348 Joules
Hence, this is the required solution.