Physics Problems

Please see the attached file for full problem description.

Current and Resistance

1. In a particular television tube, the beam current is 60.0 pa(the "p" is the closest I could get to making it look like the actual symbol, its like a p but doesn't have a top, its more like a u). How long does it take for 3.75 x 10^14 electrons to strike the screen? 2. A stereo with a resistance of 65 (the symbol loo ...continues

resistance

1. An ammeter registers 2.5 A of current in a wire that is connected to a 9.0 V battery. What is the wire's resistance? 2. A small electronic device is rated at 0.25 W when connected to 120 V. What is the resistance of this device? Please include the answers, formulas used and work done. Thank you!

Geometrical Optics

A small insect is placed 5.41cm from a +6.59cm focal length lens. Calculate the position of the image. Calculate the angular magnification.

optics

Reading glasses of what power (D) are needed for a person whose near point is 121cm, so that he can read a computer screen at 48.8cm? Assume a lens eye distance of 1.83cm.

short answer

Which kind of spherical mirror, concave or convex, can be used to start a fire with sunlight? and for the best results, how far from the mirror should the paper to be ignited be placed? Explain your answers.

answer in degrees

A person stands 3.4 m in front of a wall that is covered floor-to-ceiling with a plane mirror. His eyes are 2.0 m above the floor. He holds a flashlight between his feet and manages to point it at the mirror. At what angle of incidence must the light strike the mirror so the light will reach his eyes?

answer in cm The image of a very distant car is located 24 cm behind a convex mirror. What is the radius of curvature of the mirror?

The image of a very distant car is located 24 cm behind a convex mirror. What is the radius of curvature of the mirror?

answer in cm

The image of a very distant car is located 24 cm behind a convex mirror. What is the radius of curvature of the mirror?

answer in meters

Convex mirrors are being used to monitor the aisles in a store. The mirrors have a radius of curvature of 4 m. What is the image distance if a customer is 15 m in front of the mirror?