The intensity of a 50-dB whistle is doubled. What is the new decibel level?

a. 50 dB
b. 47 dB
c. 53 dB
d. 100 dB


c

Physics & Space Science

You might also like to view...

For an ideal radiator (hohlraum) with a 10-cm-diameter opening, located in black surroundings at 16°C, (a) calculate the net radiant heat transfer rate for hohlraum temperatures of 100°C and 560°C, (b) the wavelength at which the emission is a maximum, (c) the monochromatic emission at ?max, and (d) the wavelengths at which the monochromatic emission is 1 per cent of the maximum value.

GIVEN
• An ideal radiator (hohlraum) in black surroundings
• Radiator opening diameter (D) = 10 cm = 0.1 m
• Surrounding temperature (Ts) = 16°C = 289 K
• Hohlraum temperatures
- Th1 = 100°C = 373 K
- Th2 = 560°C = 833 K
FIND
(a) The net radiant heat transfer rate (qr)
(b) The wavelength at which the emission is maximum (?max)
(c) The monochromatic emission at ? max (E?max)
(d) The wavelengths at which the monochromatic emission is 1% E?max
SKETCH

PROPERTIES AND CONSTANTS
the Stephan-Boltzmann constant (?) = 5.67 × 10–8 W/(m2 K4)

Physics & Space Science

The figure shows a cross section of three parallel wires each carrying a current of 5.0 A out of the paper. If the distance R = 6.0 mm, what is the magnitude of the magnetic force on a 2.0-m length of any one of the wires?



a.
2.5 mN

b.
3.3 mN

c.
2.2 mN

d.
2.9 mN

e.
1.7 mN

Physics & Space Science

Type Ia and Type Ib supernovae both involve binary star systems

a. True b. False Indicate whether the statement is true or false

Physics & Space Science

Explain two methods that could be used to find the spring constant of a spring experimentally

Physics & Space Science