This means that two objects will reach the ground at the same time if they are dropped simultaneously from the same height. ... When air resistance plays a role, the shape of the object becomes important. In air, a feather and a ball do not fall at the same rate.
Answer:
Therefore the direction is in the <u>positive direction of the z axes</u>.
Explanation:
Let's recall that the magnetic force is given by:

The unit vector of V is
and the unit vector of B is 
So, the direction of the force will be defined as the cross product of i and j, and using the right hand rule:
Therefore the direction of the magnetic force is in the <u>positive direction of the z axes</u>.
I hope it helps you!
Ep= mgh
Ep = 40 x 9.8 x 10
Ep = 3920J
Ep = 3900J (2sf)