Introduction To Health Physics
5th Edition
ISBN: 9780071835275
Author: Johnson, Thomas E. (thomas Edward), Cember, Herman.
Publisher: Mcgraw-hill Education,
expand_more
expand_more
format_list_bulleted
Concept explainers
Videos
Textbook Question
thumb_up100%
Chapter 2, Problem 2.38P
How much sub-butuminous coal (20,000 kJ/kg) would it take to generate the electricity needed to keep a 100 W light bulb lit for 1 year if the overall efficiency of the generating station is 30%?
Expert Solution & Answer
Want to see the full answer?
Check out a sample textbook solution
Students have asked these similar questions
The 20-W LED bulb can provide the same amount of light output as the 100-W incandescent light bulb. How much percentage you could save for using the LED bulb in place of the incandescent bulb for one year, assuming ₱7.50 per kilowatt-hour is the average energy rate charged by the power company? Assume that the bulb is turned on for 7 hours a day.
a.) 20%
b.) 80%
c.) 150%
d.) none of the above
A typical incandescent reading lamp runs at 60W. If it is lefton constantly, how much energy (J) is consumed per day,and what is the weekly cost if energy is charged at a rate of12.5 cents per kilowatthour?
you are standing 2.5 m from a 150-W lightbulb. If the pupil of your eye is a circle 5.0 mm diameter, how much energy enters your eye per second? (assume 5.0% of the lightbulb's power is converted to light)
Chapter 2 Solutions
Introduction To Health Physics
Ch. 2 - Two blocks of mass 0.1 kg and 0.2 kg approch each...Ch. 2 - A bullet whose mass is 50 g travels at a velocity...Ch. 2 - Compute the mass of the Earth, assuming it to be a...Ch. 2 - An automobile weighing 2000 kg and going at a...Ch. 2 - A small electrically charged sphere of mass 0.1 g...Ch. 2 - A capacitor has a capacitance of 10F . How much...Ch. 2 - A small charged particle whose mass is 0.01 g...Ch. 2 - Prob. 2.8PCh. 2 - Prob. 2.9PCh. 2 - Prob. 2.10P
Ch. 2 - Prob. 2.11PCh. 2 - Prob. 2.12PCh. 2 - Prob. 2.13PCh. 2 - Prob. 2.14PCh. 2 - Prob. 2.15PCh. 2 - A current of 25 mA flows through a 25-gauge wire,...Ch. 2 - An electron starts at rest on the negative plate...Ch. 2 - Prob. 2.18PCh. 2 - Prob. 2.19PCh. 2 - Prob. 2.20PCh. 2 - Prob. 2.21PCh. 2 - Prob. 2.22PCh. 2 - Prob. 2.23PCh. 2 - (a) A 1000-MW(e) nuclear power plant operates at a...Ch. 2 - Prob. 2.25PCh. 2 - Prob. 2.26PCh. 2 - Prob. 2.27PCh. 2 - The specific heat of water in the English system...Ch. 2 - Prob. 2.29PCh. 2 - Prob. 2.30PCh. 2 - Prob. 2.31PCh. 2 - Prob. 2.32PCh. 2 - How many cubic meters of water must fall over a...Ch. 2 - (a) Calculate the speed of a 25-MeV proton. (b)...Ch. 2 - Prob. 2.35PCh. 2 - Prob. 2.36PCh. 2 - Calculate the speed of a (a) 0.5-MeV electron and...Ch. 2 - How much sub-butuminous coal (20,000 kJ/kg) would...Ch. 2 - Prob. 2.40PCh. 2 - How much oil (138,690 Btu/gal) would it take to...Ch. 2 - How much oil (138,690 Btu/gal) would it take to...Ch. 2 - Prob. 2.43PCh. 2 - Prob. 2.44PCh. 2 - Prob. 2.45PCh. 2 - Prob. 2.46PCh. 2 - Prob. 2.47PCh. 2 - Prob. 2.48PCh. 2 - Prob. 2.49P
Knowledge Booster
Learn more about
Need a deep-dive on the concept behind this application? Look no further. Learn more about this topic, physics and related others by exploring similar questions and additional content below.Similar questions
- A solar cell has a light-gathering area of 10 cm² and produces 0.2 A at 0.8 V (DC) when illuminated with S= 1 000 W/m² sunlight. What is the efficiency of the solar cell? 16% 7% 23% 4% 32%arrow_forward(1) An incandescent light bulb produces 5.85 Joules of light energy each second. This bulb is 7.80% efficient, meaning that only 7.80% the total energy it consumes becomes light and the rest becomes waste heat. A 12.0 W fluorescent bulb is designed to produce the same illumination (in Joules of light energy per second) as the incandescent bulb. A large building uses 17,530 light bulbs. At a cost of 8.56€/kW-hr for electricity, how much money will the owners of the building save each year if they use fluorescent bulbs instead of incandescent bulbs? Express your answer in dollars. [answer: about $828,000]arrow_forwardA 9 W led lightbulb emits the same light as a 60 W standard lightbulb. If a power company charges 10 cents per kW.h, then how much money do you save by using the led lightbulb instead of the standard lightbulb for 30 days?arrow_forward
- A solar panel of length L and width W produces 28.4 kWh in a day. Under the same conditions (i.e. the same amount of solar energy available and the same efficiency) a solar panel of length 2L and width 2W would produce how many kWh in a day? Round off your answer to 2 decimal places, but do not write the unit.arrow_forwardIn Washington, a solar panel facing south angled at 15 degrees receives 0.5 (+/- 0.5) kWh/m^2/day in the winter. Solar panels are 20% efficient. Another 20% of power is lost due to heat. A house uses 45 kW per day in the winter. What is the minimum number of panels needed?arrow_forwardA monthly electric bill is based on the following usage: A set of electronic devices that altogether are rated at 1,812 W. The devices are ON 12 hours a day. A set of light of total power 562 W that are on 24 hours a day. What would be the value of the bill if we count one month as 30 days and electricity costs $0.08 /kWh. Write down your answer as an amount of dollars rounded off to an integer value ( no decimals) and do not put any unit.arrow_forward
- Suppose a battery operates a 2.25 W electric clock for 19.5 months. 1. What is the available energy content, in joules, of the battery? 2. How many years can a battery that supplies 7.75 × 104 J run a pocket calculator that consumes energy at the rate of 1.05 × 10-3 W?arrow_forwardAn incandescent lightbulb is an inexpensive but highly inefficient device that converts electrical energy into light. It converts about 10 percent of the electrical energy it consumes into light while converting the remaining 90 percent into heat. The glass bulb of the lamp heats up very quickly as a result of absorbing all that heat and dissipating it to the surroundings by convection and radiation. Consider an 8-cm-diameter 60-W lightbulb in a room at 25°C. The emissivity of the glass is 0.9. Assuming that 10 percent of the energy passes through the glass bulb as light with negligible absorption and the rest of the energy is absorbed and dissipated by the bulb itself by natural convection and radiation, determine the equilibrium temperature of the glass bulb. Assume the interior surfaces of the room to be at room temperature.arrow_forwardA solar panel measures 80 cm x 50 cm. In direct sunlight, the panel delivers 3.2 A at 15 V. If the intensity of sunlight is 1 000 W/m2, what is the efficiency of the solar panel in converting solar energy into electrical energy?arrow_forward
- An 11 W LED light bulb has an efficiency of 30 %. What amount of energy is wasted if the bulb is operated continuously for 1 minute?arrow_forwardA typical cost for electric power is $ 0.135 per kilowatt-hour. (a) Some people leave their porch lights on all the time. What is the yearly cost to keep a 75-W bulb burning day and night? (b) Suppose a refrigerator uses 400W of power when it’s running, and it runs 8 hours a day. What is the yearly cost of operating that refrigerator?arrow_forwardAn electric water heater is designed to produce 48 kWkW of heat when it is connected to a 240-V source. If the heater is 88 %% efficient, how long would it take to heat 51 galgal of water from 20∘C∘C to 60 ∘∘? Express your answer using two significant figures.arrow_forward
arrow_back_ios
SEE MORE QUESTIONS
arrow_forward_ios
Recommended textbooks for you
Physics for Scientists and Engineers: Foundations...PhysicsISBN:9781133939146Author:Katz, Debora M.Publisher:Cengage Learning
Physics for Scientists and Engineers: Foundations...
Physics
ISBN:9781133939146
Author:Katz, Debora M.
Publisher:Cengage Learning
Ohm's law Explained; Author: ALL ABOUT ELECTRONICS;https://www.youtube.com/watch?v=PV8CMZZKrB4;License: Standard YouTube License, CC-BY