Answer:
Compression in the spring, x = 0.20 m
Explanation:
Given that,
Spring constant of the spring, k = 490 N/m
Mass of the block, m = 5 kg
To find,
Compression in the spring.
Solution,
Since the block is suddenly dropped on the spring gravitational potential energy of block converts into elastic potential energy of spring. Its expression is given by :

Where
x is the compression in the spring


x = 0.20 m
So, the compression in the spring due to block is 0.20 meters.
B) at the poles of the magnet
Answer:
Explanation:
Calculate the volume of the lead

Now calculate the bouyant force acting on the lead


This force will act in upward direction
Gravitational force on the lead due to its mass will act in downward direction
Hence the difference of this two force

If V is the volume submerged in the water then bouyant force on the bobber is

Equate bouyant force with the tension and gravitational force

Now Total volume of bobble is

=
To solve this problem we will apply the concepts of energy conservation and Newton's second law that defines force as the product of the object's mass with its acceleration. Additionally we will apply concepts related to the kinematics equations of linear motion.
For conservation of energy we have that work is equal to kinetic energy therefore,


Here,
F = Force
d = Displacement
m = Mass
v= Velocity
At the same time we have the relation of

Therefore the value of the force can be interpreted as the rate of increase in energy per unit of distance, which makes it equivalent to

Applying Newton's Second Law



In 4 seconds final velocity of the object becomes



Then the work done is equal to,




Then the displacement is,




Therefore the distance moved is 16m
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