Answer:
2.55 m
Explanation:
Elastic energy = gravitational energy
½ kx² = mgh
h = kx² / (2mg)
h = (200 N/m) (0.05 m)² / (2 × 0.010 kg × 9.8 m/s²)
h = 2.55 m
Answer:
New force, 
Explanation:
The electrostatic force between two spheres is given by :
According to given condition, each of the spheres has lost half its initial charge, new force is given by :
So, the new force becomes (1/4)th of the initial force. Hence, the correct option is (d).
Answer:
4) True. The change of direction needs an unbalanced force
Explanation:
Let us propose the resolution of the problem using Newton's second law.
F = m a
As the car is spinning the acceleration is centripetal
a = v2.r
F = m v2 / r
We can see that as the velocity of a vector even if its module does not change, the change of direction requires an external force.
Now we can analyze the statement if they are true or false
1) and 3) False, even when the speed changes, the direction changes
2) False with the speed change can be determined
4) True. The change of direction needs an unbalanced force
5) False are different things. the direction is where it is going and the speed is the magnitude of the vector
