Question

In: Physics

#1 A microwave oven has a power requirement of 1,261 W. A frozen dinner requires 4.1...

#1 A microwave oven has a power requirement of 1,261 W. A frozen dinner requires 4.1 min to heat on full power.

(a) How much electrical energy (in kWh) is used?
_________kWh

(b) If the cost of electricity is 13¢ per kWh, how much does it cost to heat the dinner? (Do not round your final answer. Fractional cent values are acceptable.)
______________¢

#2 - A student who weighs 556 N climbs a stairway (vertical height of 2.6 m) in 23 s.

(a) How much work is done?
__________J

(b) What is the power output of the student?
__________W

Solutions

Expert Solution

The concept used is of energy consumed and power , initially i calculate the energy consumed by the dinner in joule after that i converted it in to kWh and i also mention the meaning of one kWh  which means one unit of electricity , as cost of one unit of electricity is given then i used it to calculate the cost of electricity .

kindly upvote my answer , if you like by clicking on the like button.


Related Solutions

Application: Heating Food in a Microwave Oven. A frozen pizza is marketed to be heated in...
Application: Heating Food in a Microwave Oven. A frozen pizza is marketed to be heated in a microwave oven. As an engineer you are asked to write heating instructions, specifically how long should it be heated to reach a proper temperature. The average residential microwave oven is 50 cm wide, 40 cm deep, and 30 cm high. The oven has a low and a high heating level. At low, it produces a time averaged power of 500 W, whereas at...
200g of water at 30°C is put in a 1000 W (J/s) microwave oven. For simplicity...
200g of water at 30°C is put in a 1000 W (J/s) microwave oven. For simplicity assume that all the energy produced by the microwave goes into the water. The microwave runs for 2 minutes. Constants for H2O: TMP=0°C, TBP=100°C, ΔHmelt = 333.5 kJ/kg, ΔHvap = 2257 kJ/kg, cliquid=4.18 kJ/kgK, cgas=1.87 kJ/kgK. a) Calculate the total amount of energy transferred to the water. Show your work. b) Draw the Three-Phase Diagram (temperature versus energy added) and label the initial state...
9. A microwave oven has a frequency of 2450 Hz. You can use mini-marshmallows to locate...
9. A microwave oven has a frequency of 2450 Hz. You can use mini-marshmallows to locate the nodes of the standing wave inside the microwave. Describe how to measure the speed of light using mini-marshmallows and a microwave oven.
A 2400-W oven is connected to a 240-V source. 1. What is the resistance of the...
A 2400-W oven is connected to a 240-V source. 1. What is the resistance of the oven? Express your answer to two significant figures and include the appropriate units. 2. How long will it take to bring 110 mL of 25 ∘C water to 100∘C assuming 65 % efficiency? The specific heat capacity of water is 4186 J/(kg⋅∘C). Express your answer using two significant figures. 3. How much will this cost at 12 cents/kWh? Express your answer using two significant...
1. Bernard ran an experiment to test optimum power and time settings for microwave popcorn. His...
1. Bernard ran an experiment to test optimum power and time settings for microwave popcorn. His goal was to deliver popcorn with fewer than 11​% of the kernels left​ unpopped, on average. He determined that power 9 at 4 minutes was the best combination. To be sure that the method was​ successful, he popped 8 more bags of popcorn​ (selected at​ random) at this setting. All were of high​quality, with the percentages of unpopped kernels shown below. 3.3, 7.5, 11.3,...
A normalized message signal has a bandwidth of W = 10 KHz and a power of...
A normalized message signal has a bandwidth of W = 10 KHz and a power of Pm= 0.75 . It is required to transmit this signal via a channel with an available bandwidth of 80 KHz and attenuation of 50 dB. The channel noise is additive and white with a power-spectral density of N0/2 = 10^(-10) watts/Hz. A frequency-modulation scheme, with no pre-emphasis/de-emphasis filtering, has been proposed for this purpose. 1. If it is desirable to have an SNR of...
A processor has a clock rate of 2.5 GHz. It’s dynamic power is 80 W and...
A processor has a clock rate of 2.5 GHz. It’s dynamic power is 80 W and static power is 20 watt. It executes a certain program in 25 seconds. a. What is the power consumption if clock frequency is slowed down by 30%? b. What will be the new execution time for the program which earlier took 25 seconds after slowing down the clock as in part a? c. What is the power consumption if voltage is decreased by 15%?
Karim Corp. requires a minimum $8,200 cash balance. Loans taken to meet this requirement cost 1%...
Karim Corp. requires a minimum $8,200 cash balance. Loans taken to meet this requirement cost 1% interest per month (paid monthly). Any excess cash is used to repay loans at month-end. The cash balance on July 1 is $8,600, and the company has no outstanding loans. Forecasted cash receipts (other than for loans received) and forecasted cash payments (other than for loan or interest payments) follow. July August September Cash receipts $ 24,200 $ 32,200 $ 40,200 Cash payments 28,300...
1) W XYZ Limited is evaluating Project X , which requires an initial investment of RO40,000...
1) W XYZ Limited is evaluating Project X , which requires an initial investment of RO40,000 . The expected net cash flows are RO15,000 pa for five years at today's prices . However these are expected to rise by 6.0 % pa because of inflation . The firm's cost of capital is 13 % . Find the NPV by : ( a ) discounting money cash flows ( b ) discounting real cash flows . 2) XYZ Limited is evaluating...
3. Excess capacity adjustments Water and Power Co. (W&P) currently has $540,000 in total assets and...
3. Excess capacity adjustments Water and Power Co. (W&P) currently has $540,000 in total assets and sales of $1,550,000. Half of W&P’s total assets come from net fixed assets, and the rest are current assets. The firm expects sales to grow by 22% in the next year. According to the AFN equation, the amount of additional assets required to support this level of sales is $_________ . W&P was using its fixed assets at only 93% of capacity last year....
ADVERTISEMENT
ADVERTISEMENT
ADVERTISEMENT