Physics Answers

An object is 3cm in front of a convex lens with 2cm focal length.

Find: a) the image distance

B)the magnification.

C)the image description: real or virtual? erect or inverted?

A flashlight underwater (n=1.43) is aimed at the surface with incident angle 30°. What is the angle of refraction in the air (n=1) ?

Find the quantum ( photon) energy associated with a 650.kHz AM radio signal.

A car, with it's horn producing 480.Hz, is traveling 40.0mi/h away from you (standing still). What frequency do you hear, given the speed of sound is 1090.ft/s ?

If a 20dB sound level (ticking clock) is replaced by 80dB (garbage disposal), by what factor has the sound intensity been multiplied?

A catapult consists of a rubber of unstretched length, 0.20m. The rubber is stretched by 0.10m by a tension of 50N. A stone of mass 0.06Kg is projected vertically upwards from the catapult after the rubber has been stretched to a total length of 0.35m. Calculate the energy stored in the stretched catapult and determine the maximum height reached by the stone.

4.5m of air a gauge pressure 46.kPa undergoes an isothermal expansion to where the gauge pressure drops to 13.kPa. Calculate the final volume in m3

1270.cm of propane at 18.0°C are heated and allowed to expand to 1530.cm through an isobaric process. Calculate the final temperature in °C.

How many calories of heat need to be extracted from 200.g of steam at 120.°C to change it into ice at --12.0°C ?

The plates of a parallel – plate capacitor uses a disk with a radius of 10mm. The separation distance between the plates is 100 nm and between the plates is a sheet of mica. What is the capacitance of the capacitor?