Assume the mostly infrared radiation from a heat lamp is IR-B and acts like a continuous wave with wavelength 2.90 μm.(a) If the lamp's 220 W output is focused on a person's shoulder, over a circular area 24.0 cm in diameter, calculate the intensity in(W/m²).W/m²(b) The shoulder area has a mass of 3.75 kg. Assume no other heat transfer and given its specific heat is 3.47 × 10³ J/(kg •°C), calculatethe change in temperature if the shoulder is radiated for a time of 45.0 s.°C

Need to find: Intensity change in temperature.

Answered: Assume the mostly infrared radiation…

Similar questions

Optical tweezers use light from a laser to move single atoms and molecules around. Suppose the intensity of light from the tweezers is 1000 W/m², the same as the intensity of sunlight at the surface of the Earth. (a) What is the pressure on an atom if light from the tweezers is totally absorbed? Pa (b) If this pressure were exerted on a helium atom, what would be its acceleration? (The mass of a helium atom is 6.65 x 10-27 kg. Assume the cross-sectional area of the laser beam is 6.65 x 10-29 m².) m/s²
Suppose the maximum safe average intensity of microwaves for human exposure is taken to be 1.00 W/m2. If a radar unit leaks 10.0 W of microwaves (other than those sent by its antenna) uniformly in all directions, how far away, ?min, must you be to be exposed to an average intensity considered to be safe? Assume that the power spreads uniformly over the area of a sphere with no complications from absorption or reflection. ?min= m What is the maximum electric field strength ?0 at this distance? The permittivity of free space is ?0=8.854×10−12 C2/(N·m2). The speed of light is ?=3.00×108 m/s. ?0= V/m Note: Early radar units leaked more than modern ones do. This caused identifiable health problems, such as cataracts, for people who worked near them.
Optical tweezers use light from a laser to move single atoms and molecules around. Suppose the intensity of light from the tweezers is 1000 W/m², the same as the intensity of sunlight at the surface of the Earth. (a) What is the pressure on an atom if light from the tweezers is totally absorbed? Pa (b) If this pressure were exerted on a tritium atom, what would be its acceleration? (The mass of a tritium atom is 5.01 x 107 -27 kg. Assume the cross-sectional area of the laser beam is 6.65 x 10-2⁹ m².) m/s²
Assume the mostly infrared radiation from a heat lamp acts like a continuous wave with wavelength 1.50 µm. (a) If the lamp's 205 W output is focused on a person's shoulder, over a circular area 24.0 cm in diameter, what is the intensity in W/m2? 2266.9 W/m2 (b) What is the peak electric field strength in kV/m? 0.924 X kV/m (c) Find the peak magnetic field strength in µT. 3.08 X µT (d) How long will it take in seconds to increase the temperature of the 3.80 kg shoulder by 2.00°C, assuming no other heat transfer and given specific heat is 3.47 x 103 J/(k • °C)? 128.64
Suppose the maximum safe intensity of microwaves for human exposure is taken to be 1.81 W/m2. If a radar unit leaks 10.0 W of microwaves (other than those sent by its antenna) uniformly in all directions, how far away must you be to be exposed to an intensity considered to be safe? Assume that the power spreads uniformly over the area of a sphere with no complications from absorption or reflection. (Note that early radar units leaked more than modern ones do. This caused identifiable health problems, such as cataracts, for people who worked near them.)
Suppose the maximum safe average intensity of microwaves for human exposure is 1.00 W/m2. Early radar units leaked radiation more than modern ones do, which caused identifiable health problems, such as cataracts, for people who worked near them. Part (a) If a radar unit leaks 6.5 W of microwave radiation uniformly in all directions, what is the closest distance, in centimeters, you can be to the unit and still be considered safe? Assume that the power spreads uniformly over the area of a sphere with no complications from absorption or reflection. Part (b) What is the maximum electric field strength E0, in volts per meter, of the microwave radiation at the maximum safe intensity?
An AM radio transmitter broadcasts 54.0 kW of power uniformly in all directions. (a) Assuming all of the radio waves that strike the ground are completely absorbed, and that there is no absorption by the atmosphere or other objects, what is the intensity (in W/m2) 26.0 km away? (Hint: Half the power will be spread over the area of a hemisphere.) W/m2 (b) What is the maximum electric field strength (in V/m) at this distance? V/m