Light of wavelength 575 nm passes through a double-slit and the third order bright fringe is seen at an angle of 6.5 away from the central fringe. What is the separation between the double slits?
A) 5.0 m
B) 10 m
C) 15 m
D) 20 m
E) 25 m
Question 2
A blacksmith is flattening a steel plate that measures 10 cm 15 cm 1 mm. He has heated the plate to 900 K. If the emissivity of the plate is 0.75,
what is the total rate at which it radiates energy? The Stefan-Boltzmann constant is 5.670 10-8 W/m2 K4. Ignore any heat it receives from the surroundings.
A) 360 W
B) 760 W
C) 790 W
D) 850 W
E) 880 W