1. If you eat 750 calories of food and then run up several steps of stairs...

Transcribed Image Text:

1. If you eat 750 calories of food and then run up several steps of stairs to work off the energy you taken in. How high do you climb if your mass is about 55kg? Assume 80% efficiency in the conversion of food energy into mechanical work. 2. A computer CPU chip is heated from 15°C to 70°C as computer is turned on. How much energy did the heating require? A computer CPU chip is consisting of 50g silicon, 20g copper and 50g polyvinyl chloride (plastic). 3. What is the change in internal energy of a car if you put 12 gallons of gasoline into its tank? The energy content of gasoline is 1.3 x 108 Consider other factors such as car temperature as constant. gal 4. Suppose a female worker does 500J of work and 9500J of heat transfer occurs into the environment during the process, (a) what is the decrease in her internal energy assuming no change in temperature or consumption of food? (b) What is her efficiency? Concept Question: a. An automobile accelerates to 6 miles per hour in 12 sec. Is the work different if it is accelerated to 60 miles per hour in only 8 sec? Explain your answer. b. It is a hot summer day. A student leaves his dormitory room with a fan on and with the door and windows closed. When he returns in the afternoon, will the room be warmer or cooler than an identical room without the fan? Explain your answer. c. Identify the type of energy transferred to your body in each of the following as either internal, heat transfer or doing work Basking in sunlight Eating food Riding an elevator to a higher floor 1. If you eat 750 calories of food and then run up several steps of stairs to work off the energy you taken in. How high do you climb if your mass is about 55kg? Assume 80% efficiency in the conversion of food energy into mechanical work. 2. A computer CPU chip is heated from 15°C to 70°C as computer is turned on. How much energy did the heating require? A computer CPU chip is consisting of 50g silicon, 20g copper and 50g polyvinyl chloride (plastic). 3. What is the change in internal energy of a car if you put 12 gallons of gasoline into its tank? The energy content of gasoline is 1.3 x 108 Consider other factors such as car temperature as constant. gal 4. Suppose a female worker does 500J of work and 9500J of heat transfer occurs into the environment during the process, (a) what is the decrease in her internal energy assuming no change in temperature or consumption of food? (b) What is her efficiency? Concept Question: a. An automobile accelerates to 6 miles per hour in 12 sec. Is the work different if it is accelerated to 60 miles per hour in only 8 sec? Explain your answer. b. It is a hot summer day. A student leaves his dormitory room with a fan on and with the door and windows closed. When he returns in the afternoon, will the room be warmer or cooler than an identical room without the fan? Explain your answer. c. Identify the type of energy transferred to your body in each of the following as either internal, heat transfer or doing work Basking in sunlight Eating food Riding an elevator to a higher floor