Answer:
W = 20 J
Explanation:
Given that,
The mass of a loaded sack, m = 1000 g = 1 kg
It falls down from the floor of a lorry 200 cm high, h = 2 m
We need to find the work done by the gravity. The work done by an object under the action of gravity is given by :
W = mgh
Substitute all the values,
W = 1 × 10 × 2
= 20 J
Hence, the required work done by gravity is equal to 20 J.
The correct answer is A.
Quantum physics is the branch of science which deals with the behavior of matter and light on atomic and subatomic level. So, to understand the motion of an atom we would need quantum physics. Motion of a ball and a galaxy can be understood by Newtonian mechanics.
To solve the problem it is necessary to use the concepts and expressions related to the magnetic dipole moment.
It is usually defined by,

Where,
Magnetic Dipole Moment
I = Current
A = Area
In this way re-arrange for the current and replacing,




Therefore the current is
Amperes
Answer:
88 Watts
Explanation:
From the question given above, the following data were obtained:
Resistance (R) = 0.22 Ohm
Current (I) = 20 A
Power (P) =.?
P = IV....... (1)
From ohm's law,
V = IR ........ (2)
Substitute the value of V in equation (2) into equation (1)
P = IV
V = IR
P = I(IR)
P = I²R
With the above formula (i.e P = I²R), we can obtain the power lost to heat as follow:
Resistance (R) = 0.22 Ohm
Current (I) = 20 A
Power (P) =.?
P = I²R
P = 20² × 0.22
P = 400 × 0.22
P = 88 Watts
Thus, the power lost to heat is 88 Watts.
They are both Simple mechanics