Answer: 
Explanation:
Given
Cross-sectional area of wire 
Extension of wire 
Extension in a wire is given by

where, 

for same force, length and material

Divide (i) and (ii)

Answer:
28 cm and 32 cm
Explanation:
1. The spring pendulum hangs vertically, oscillates harmonic with amplitude 2cm and angular frequency 20 rad/s. The natural length of
a spring is 30cm. What is the minimum and maximum length of the spring during the oscillation? Take g = 10m/s2.
As the amplitude is 2 cm and the natural length is 30 cm. So, it oscillates between 30 -2 = 28 cm to 30 + 2 = 32 cm.
So, the minimum length is 28 cm and the maximum length is 32 cm.
Answer:
The deceleration is 
Explanation:
From the question we are told that
The height above firefighter safety net is 
The length by which the net is stretched is 
From the law of energy conservation

Where
is the kinetic energy of the person before jumping which equal to zero(because to kinetic energy at maximum height )
and
is the potential energy of the before jumping which is mathematically represented at

and
is the kinetic energy of the person just before landing on the safety net which is mathematically represented at

and
is the potential energy of the person as he lands on the safety net which has a value of zero (because it is converted to kinetic energy )
So the above equation becomes

=> 
substituting values

Applying the equation o motion

Now the final velocity is zero because the person comes to rest
So



Answer:
Distance: 1600 m Displacement: 0
Explanation:
The distance is because He ran 400 meters 4 times getting 1600 m
4*400=1600
The displacement is 0 because displacement is the total distnce away from the starting point and since he ran laps around the track in the end he ended up in the same spot as last time.