An electron moves north at a velocity of 4.5 x 104 m/s and has a magnetic force of 7.2 x 10-18 N exerted on it. If the magnetic field points upward, what is the magnitude of the magnetic field

Aplayground slide is 8.80 ft long and makes an angle of 25.0° with the horizontal. a 63.0-kg child, initially at the top, slides all the way down to the bottom of the slide. (a) choosing the bottom of the slide as the reference configuration, what is the system's potential energy when the child is at the top and at the bottom of the slide? what is the change in potential energy as the child slides from the top to the bottom of the slide? (include the sign of the value in your answer.)