The momentum p of a moving particle is the product between its mass, m, and tis velocity, v:

In our problem, we know

and

, and using the relationship mentioned above, we can find the mass m of the particle:
Answer:
1) ironing a shirt 2) writing on surfaces 3) working of an eraser
Answer:
Final velocity v = 8.944 m/sec
Explanation:
We have given distance S = 40 meters
Time t = 10 sec
As it starts from rest so initial velocity u = 0
From second equation of motion 


Now from first equation of motion
, here v is final velocity, u is initial velocity, a is acceleration and t is time
So 
A. Angular momentum is always conserved would be the correct answer.
This is because like linear momentum (mvmv), angular momentum (r×mvr×mv) is a conserved quantity, where rr is the vector from the center of rotation. For a skater holding a static pose, for each particle making up her body, the contribution in magnitude to the total angular momentum is given by mirivimirivi. Thus bringing in her arms reduces riri for those particles. In order to conserve angular momentum, there is then an increase in the angular velocity.
hope this helps!
When the diver reaches maximum height, the upward velocity will be zero.
We shall use the formula
v^2 = u^2 - 2gh
where
v = 0 (velocity at maximum height)
u = 1.2 m/s, intial upward velocity
g = -9.8 m/s^2, gravitational acceleration (downward)
h = maximum height attained above the diving board.
Therefore
0 = 1.2^2 - 2*9.8*h
h = 1.2^2/(2*9.8) = 0.0735 m
Answer: 0.074 m (nearest thousandth)