Answer:t=0.81 s
Explanation:
Given
Penguin slides down with constant velocity of 3.57 m/s
as the Penguin Slides with constant velocity therefore
is zero on Penguin

friction Force

coefficient of Kinetic friction



after reaching on floor final velocity of penguin will be zero after time t
thus

here 
(deceleration)



The answer is A. meters (m)
Answer:
The electric flux is 
Explanation:
Given:
- Radius of the disc R=0.50 m
- Angle made by disk with the horizontal

- Magnitude of the electric Field

The flux of the Electric Field E due to the are dA in space can be found out by using Gauss Law which is as follows

where
is the total Electric Flux- E is the Electric Field
- dA is the Area through which the electric flux is to be calculated.
Now according to question we have

Hence the electric flux is calculated.
Choices 'C' and 'D' are both correct.
(Except in 'C', changing the temperature from 1°C to 3°C is not usually
described as 'cooling', and it's not the water's 'mass' that changes. But
water does contract in volume during that change.)