An immersion heater used to boil water for a single cup of tea plugs into a 120 v outlet and is rated at 400 w . suppose your super-size, super-insulated tea mug contains 400 g of water at a temperature of 23 ∘c. you can ignore the energy needed to raise the temperature of the mug and the heater itself. what is the resistance of the heater?

how long will this heater take to bring the water to a boil?

An athlete swings a ball, connected to the end of a chain, in a horizontal circle. the athlete is able to rotate the ball at the rate of 8.13 rev/s when the length of the chain is 0.600 m. when he increases the length to 0.900 m, he is able to rotate the ball only 6.04 rev/s. (a) which rate of rotation gives the greater speed for the ball? 6.04 rev/s 8.13 rev/s (b) what is the centripetal acceleration of the ball at 8.13 rev/s? m/s2 (c) what is the centripetal acceleration at 6.04 rev/s? m/s2