An electron moves in a region where the magnetic field is uniform and has a magnitude of 80 ?T. The electron follows a helical path which has a pitch of 9.0 mm and a radius of 2.0 mm. What is the speed of this electron as it moves in this region?
a. 48 km/s
b. 28 km/s
c. 20 km/s
d. 35 km/s
e. 8.0 km/s
d
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A satellite, initially at rest in deep space, separates into two pieces, which move away from each other. One piece has a rest mass of 190 kg and moves away with a speed 0.280c,
and the second piece moves in the opposite direction with a speed 0.600c. What is the rest mass of the second piece? A) 88.7 kg B) 68.8 kg C) 79.6 kg D) 52.7 kg E) 73.9 kg
What basic type of reaction is illustrated by the general equation AB ? A + B?
a. Combination b. Decomposition c. Double-replacement d. Single-replacement
A large water storage container is filled to a depth of 3.0 m. The volume above the water is filled with air. In order to pump the water from the container, the air pressure in the container is increased by 3.0 105 N/m2 . What happens to the pressure in the water at a depth of 1.0 m when the air pressure is increased?
a. Nothing, it is still at a depth of 1.0 m and the pressure in the water depends only on the depth. b. It increases by 1.0 105 N/m2, since it is at 1/3 the depth of the water. c. It increases by 2.0 105 N/m2, since it is at 2/3 the depth from the bottom of the container. d. It increases by 3.0 105 N/m2. e. It increases by 3.0 105 N/m2 + 9.8 103 N/m2 since it is 1.0 m deep in the water.
A drawing is placed 40 cm in front of a thin lens. If a virtual image forms at a distance of 50 cm from the lens, on the same side as the drawing, what is the focal length of the lens?
A) -45 cm B) 75 cm C) 90 cm D) 200 cm