Doubt from work power energy

#1

Q2


Q11

#2

11-c ?
for q2 v = \sqrt{10gl} ?

#3

Yes both are right pls upload the soln

#4

Pls check ...

#5

for Q2-
We know min velocity to complete circle in vertical circular motion is \sqrt{5gl}
Here g_{eff}=g+g=2g
so v_{min}=\sqrt{10gl}

And for Q11-
E=\frac{kx^2}{2}
differentiate wrt t both sides.
20=kx \frac{dx}{dt}
\frac{dx}{dt} = v_{a}-v_{b}
x is the strech in the spring.
x=0.1m

1 Like
#6

Understood. Thank you