A little boy rides a roller coaster that makes a loop with a radius of 30.0m. The boy hits the bottom of the loop traveling at 40.0m/s. The net force on the boy is 1350N. What is the mass of the boy? 1800 kg
60 kg
1010 kg
25.3 kg

Suppose a diode consists of a cylindrical cathode with a radius of 6.200×10^−2 cm , mounted coaxially within a cylindrical anode with a radius of 0.5580 cm . the potential difference between the anode and cathode is 260 v . an electron leaves the surface of the cathode with zero initial speed (v initial=0). find its speed vfinal when it strikes the anode.