Answer:
(a)0.0675 J
(b)0.0675 J
(c)0.0675 J
(d)0.0675 J
(e)-0.0675 J
(f)0.459 m
Explanation:
15g = 0.015 kg
(a) Kinetic energy as it leaves the hand

(b) By the law of energy conservation, the work done by gravitational energy as it rises to its peak is the same as the kinetic energy as the ball leave the hand, which is 0.0675 J
(c) The change in potential energy would also be the same as 0.0675J in accordance with conservation law of energy.
(d) The gravitational energy at peak point would also be the same as 0.0675J
(e) In this case as the reference point is reversed, we would have to negate the original potential energy. So the potential energy as the ball leaves hand is -0.0675J
(f) Since at the maximum height the ball has potential energy of 0.0675J. This means:
mgh = 0.0675
0.015*9.81h = 0.0675
h = 0.459 m
The ball would reach a maximum height of 0.459 m
Answer:

Explanation:
given,
length of the ship = 120 m
length of model of the ship = 4 m
Speed at which the ship travels = 70 km/h
speed of model = ?
by using froude's law

for dynamic similarities




hence, the velocity of model will be 12.78 km/h
Answer:
Explanation:
The amplitude of resultant wave as the result of overlap of two waves depends upon the phase difference between the two. If the waves meet crest to trough , the phase difference is 180 degree or they are in opposite phase . Hence they will destroy each other . The amplitude of resultant wave can be obtained by subtracting the amplitudes of two waves. They will interfere destructively.
Amplitude of resultant gives waves = 4.6 - 2 = 2.6 cm.
Answer:

Explanation:
f = Frequency = 75 Hz
B = Magnetic field = 
d = Diameter of cell = 
t = Time taken
= Angular frequency
The expression of emf is

Emf is maximum when
and N = number of turns = 1

The maximum emf that can be generated around the perimeter of a cell in this field is 