Answer:
9.8 Joules (rounded to 2 significant figures)
Explanation:
Work done (J)= Force(N) x distance changed (m)
- Force= 9.80665 x 0.5kg
- Force= 4.90332 Newtons
- Distance changed= 5-3
- distance changed= 2m/s
--> work done= 4.90332 x 2
work done= 9.8 Joules
Momentum is conserved after the collision
Momentum of 2 Kg before collision = 2 * 3 = 6
Momentum of 4 kg before collision = 4 * -3 = -12
so 6 + -12 = 2 * -4 + 4 *x where x is velocity of 4kg marble.
4x - 8 = -6
4x = 2
x = 0.5
Velocity of 4 kg marble is 0.5 m/s after collision
The 2 kg marble will move in the opposite direction to which it was moving before the collision.
Answer:
Explanation:
Given
mass of boy=36 kg
length of swing=3.5 m
Let T be the tension in the swing
At top point 
where v=velocity needed to complete circular path
Th-resold velocity is given by 

So apparent weight of boy will be zero at top when it travels with a velocity of 
To get the velocity at bottom conserve energy at Top and bottom
At top 
Energy at Bottom 
Comparing two as energy is conserved



Apparent weight at bottom is given by

Answer:
c
Explanation:
force is how hard it is pulled or pushed