Here the block has two work done on it
1. Work done by gravity
2. Work done by friction force
So here it start from height "h" and then again raise to height hA after compressing the spring
So work done by the gravity is given as

Now work done by the friction force is to be calculated by finding total path length because friction force is a non conservative force and its work depends on total path


Total work done on it

So answer will be
None of these
Answer:
a)
, b)
, c)
,
, d) 
Explanation:
a) The gravitational force exerted by the Earth on the satellite is:



b) The centripetal acceleration of the satellite is:


c) The speed of the satellite is:



Likewise, the angular speed is:


d) The period of the satellite's rotation around the Earth is:


Answer:
potential energy
Explanation:
this is because potential energy= mgh
so when m= 2m
p.e. = 2 times the previous value
Therefore , When mass is doubled , Potential energy gets doubled. When mass is halved , Potential energy decreases by half.
Answer:
When the compass is placed below the wire, and the electric current switched on, the needle deflects in the opposite direction. If an electric current is passed through a long coil of wire (a solenoid ) a magnetic field is produced which is the same shape as that of a bar magnet.
Explanation: