Answer:
K'=4K
Explanation:
The electric potential energy is given by :

Where
k is spring constant
x is compression or extension in the spring
If the displacement of a horizontal mass-spring system is doubled, x'= 2x
New elastic potential energy :

So, new elastic potential energy 4 times the initial elastic potential energy.
Answer:
(a) Workdone = -27601.9J
(b) Average required power = 1314.4W
Explanation:
Mass of hoop,m =40kg
Radius of hoop, r=0.810m
Initial angular velocity Winitial=438rev/min
Wfinal=0
t= 21.0s
Rotation inertia of the hoop around its central axis I= mr²
I= 40 ×0.810²
I=26.24kg.m²
The change in kinetic energy =K. E final - K. E initail
Change in K. E =1/2I(Wfinal² -Winitial²)
Change in K. E = 1/2 ×26.24[0-(438×2π/60)²]
Change in K. E= -27601.9J
(a) Change in Kinetic energy = Workdone
W= 27601.9J( since work is done on hook)
(b) average required power = W/t
=27601.9/21 =1314.4W
Explanation:
a) d = ½.a.t²
200 = ½(4)t²
200 = 2t²
t² = 200/2
t² = 100
t =√100 = 10 s
b) Vt = a. t
= 4(10)
= 40 m/s
c) V av. = d/t = 200/10 = 20m/s
Answer: Their final relative velocity is -0.412 m/s.
Explanation:
According to the law of conservation,

Putting the given values into the above formula as follows.



v = 
= -0.412 m/s
Thus, we can conclude that their final relative velocity is -0.412 m/s.