Answer:
The motion of the ball relative to the ground is stationary
The motion of the ball relative to the wagon is backwards
Explanation:
To describe the motion of the ball relative to the ground, we note that
Assuming the ball is perfectly round and rotate freely, then we have
Force on the ball due to motion of the wagon = 0 N,
Then by the law of motion, an object will remain at rest when no force is applied to it
Therefore, apart from rotation of the ball, it will remain no displacement relative to the ground.
The motion of the ball relative to the wagon
Relative to the wagon, the ball appears to be moving in the opposite direction to the wagon, that is backwards.
The kinetic energy of an object of mass m moving with speed v is given by:
For the bicycle in our problem,
and
, so the kinetic energy is
Answer:
A. Zero
Explanation:
The force on a coil of N turns, enclosing an area, A and carrying a current I in the presence of a magnetic field B, is :
F = N * I * A * B * sinθ
Where θ is the angle between the normal of the enclosed area and the magnetic field.
Since the normal of the area is parallel to the magnetic field, θ = 0
Hence:
F = NIABsin0
F = 0 or Zero
