An electron moving horizontally to the right with speed v enters a region where a uniform magnetic field exists pointing into the page with magnitude b. As a result the electron executes uniform circular motion with radius r. What is the total work done by the magnetic field during a half cycle of the electron’s motion in the field?

While goofing off at the ice skating rink, a student takes off her shoes and places each of them on the ice. her friend, a hockey player, then shoots a hockey puck at each shoe. the first puck immediately comes to rest after it collides with the left shoe. the second puck rebounds after it collides with the right shoe. if each hockey puck has the same incoming speed, which shoe has greater speed after the collision? the right shoe. both shoes have the same speed. the left shoe.

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.)

The chart shows daniela’s run through her race. what is her velocity? 1.5 m/s 2 m/s 2.5 m/s 5 m/s