Before going to answer this question first we have to know the fundamental principle of magnetism.
A magnet have two poles .The important characteristic of a magnet is that like poles will repel each other while unlike poles will attract each other.
Through this concept the question can be answered as explained below-
A-As per first option the side of magnet A is repelled by the south pole of magnet B. Hence the pole of a must be south .It can't be north as it will lead to attraction.
B-The side of magnet A is repelled by the north pole of magnet B. Hence the side of A must be north pole.It can't be a south pole.
C-The side of magnet A is attracted by the south pole of magnet B .Hence the side of magnet A must be north.Hence this is right
D-The side of magnet A is attracted by the north pole of magnet B. Hence the side of A must south.It can't be north as it will lead to repulsion.
Hence the option C is right.
Answer:
The force applied is 32 N
Explanation:
F = ma
F = 8 × 4
F = 32 N
data which is expressed in form of following way
here in above expression
= true value
= uncertainty in the value
now the relative uncertainty is given as
now by above formula we can say
a) 2.70 ± 0.05cm
here
True value = 2.70
uncertainty = 0.05
Relative uncertainty = 
= 0.0185
b) 12.02 ± 0.08cm
here
True value = 12.02
uncertainty = 0.08
Relative uncertainty = 
= 0.00665
Yes, this is correct Answer.
Explanation:
If we assume negligible air resistance and heat loss, we can assume that all of the Gravitational potential energy of the ball will turn into Kinetic energy as it falls toward the ground.
Therefore our Kinetic energy = mgh = (10kg)(9.81N/kg)(100m) = 9,810J.
