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:

Explanation:
Given that,
The velocity of an astronaut in a circular path, v = 16 m/s
The radius of the accelerator, r = 8 m
We need to find his centripetal acceleration. The formula that is used to find the centripetal acceleration is given by :

So, the required centripetal acceleration is
.
Answer:
length f′0 when the eye is presbyopic and by a screen (the retina) at the distance d from the
Explanation: