Answer:
Part a)

Part b)

Explanation:
As per momentum conservation we know that there is no external force on this system so initial and final momentum must be same
So we will have




Part b)
By equation of kinetic energy we have




The answer is A
Explanation: the conservation of matter means that the mass stays the same
Answer:
Explanation:
position of centre of mass of door from surface of water
= 10 + 1.1 / 2
= 10.55 m
Pressure on centre of mass
atmospheric pressure + pressure due to water column
10 ⁵ + hdg
= 10⁵ + 10.55 x 1000 x 9.8
= 2.0339 x 10⁵ Pa
the net force acting on the door (normal to its surface)
= pressure at the centre x area of the door
= .9 x 1.1 x 2.0339 x 10⁵
= 2.01356 x 10⁵ N
pressure centre will be at 10.55 m below the surface.
When the car is filled with air or it is filled with water , in both the cases pressure centre will lie at the centre of the car .
Answer:
a) iv. Displacement per unit time
b) ii. m/s2
c) this question is wrong
d) iv. m