Please help! A 250 Watt heating coil runs for 2 seconds when the pulser is turne
ID: 2277040 • Letter: P
Question
Please help!
A 250 Watt heating coil runs for 2 seconds when the pulser is turned on. How many Joules of heat does the water absorb from the coil? [Assume all the heat produced is absorbed.] A metal cup with hot water is set out on the counter in a cool room and its temperature measured overtime with a temperature probe. What do you think the graph of temperature versus time would look like? A hot object is dropped into cold water. After a long time, how do the temperature of the object and the temperature of the water it is in compare? You may assume the water and object are insulated from the outside. Two identical heating coils are placed in two insulated containers, one containing 200 g of water, the other containing 400 g of water. Both coils are run for the same length of time and the final temperatures of the water measured. How do the amounts of heat added to the two containers compare? How do you think the temperature changes for the two water samples compare?Explanation / Answer
a)heat=power *t =250*2=500 joules
b) the graph of temperature VS time will be a exponentially decreasing function
c) temp of body and water changes significantly so that they both reach same temperature finally ie body temperature reduces and water temperature increases
4)a)as the coils are identical and the time for the burining of the coils are same so heat addeed to both the containers are same
b) temerature of the container containing 200g of water will be high because there is less water content in it than the other containing 400g