They may be changed because they may find evidence of some thing that will change their perspective on things.
Answer:
The block didn't slide due to balancing of gravitational force with friction force
Explanation:
When the block was given a flick the force provided an acceleration to it and it moved up the inclined plane. when the block reached top it was expected that it would slide back but it didn't this happened because of the frictional force acting on the bottom the block which was balancing the gravitational force component along the plane and this prevented sliding back of the block.
static friction was balancing mg*sin(theta)
fs = mg*sin(theta)
Answer: potential energy but no kinetic energy
Explanation:
Since the rock is stationary, velocity is zero, therefore no kinetic energy,but there's potential energy because the rock is at rest,
Answer:
Wheel A.
Explanation:
The lesser the moment of inertia, the greater the angular acceleration. Then, the moments of inertia of each wheel are described below:
Wheel A

Wheel B


The wheel A accelerates faster in response to the torque.
Answer:
Please refer to the figure.
Explanation:
The magnitude of the magnetic field can be found by Biot-Savart Law. We should divide the loop into four components. Each component has a similar solution but their directions are quite different.
The directions can be found by right-hand rule. Point your index finger into the direction of current, point your middle finger towards the target point (0,0,a). Your thumb will show you the direction of magnetic field.