Answer:The speed if hailstone dependly largely on its size. A hailstone with a diameter of 0.39 inches,falls wit a speed of 20mph while a hailstone with 3.1 inches in diameter falls at a speed of 110mph.
No speed does not depend on the distance that the hailstone falls.
Explanation: There are other factors that affect the speed of the falling hailstone apart from its size.They are:
1. Friction between the air and the hailstone
2. Wind condition( windy or moist air)
3. The rate at which it melts falling.
Assume that the small-massed particle is 
and the heavier mass particle is 
.
Now, by momentum conservation and energy conservation:
Now, there are 2 solutions but, one of them is useless to this question's main point so I excluded that point. Ask me in the comments if you want the excluded solution too.
So now, we see that 
and 
. So therefore, the smaller mass recoils out.
Hope this helps you!
Bye!
Answer:
Upward force on the boy will be 1024 N
Explanation:
We have given mass of the boy m = 80 kg
Acceleration due to gravity 
It is given that elevator is ascending with acceleration of 
So net acceleration on the boy = 9.8+3 = 12.8 
( As the car elevator is moving ascending )
So upward force on the boy will be equal to F = m(g+a)
So 
So upward force on the boy will be 1024 N
Answer:
Explanation:
Far point = 17 cm . That means he can not see beyond this distance .
He wants to see at an object at 65 cm away . That means object placed at 65 has image at 17 cm by concave lens . Using lens formula
1 / v - 1 / u = 1 / f
1 / - 17 - 1 / - 65 = 1 / f
= 1 / 65 - 1 / 17
= - .0434 = 1 / f
power = - 100 / f
= - 100 x .0434
= - 4.34 D .
