Physics Answers

A simple AC generator consists of 20 coils of wire with an area of 1000 cm² and placed in a region where the magnetic field is 0.5 T. What would be the rotational frequency to generate a peak electromotive force of 220 V?

You are on the south side of a river that is 100m wide and following at 2m/s towards the east. Your boat can travel at 5m/s relative to the water. You want to land your boat on the north shore of the river at a point that is 40m [w] of your original position. Draw and label a diagram of the situation

there is a potential difference of v = 20 V across a resistor with r = 50 ohms. what is the current through the resistor

Two trains on separate tracks move toward each other. Train 1 has a speed of 130 km/h; train 2, a speed of 90.0 km/h. Train 2 blows its horn, emitting a frequency of 500 Hz. What is the frequency heard by the engineer on train 1 when the air temperature is 16^oC?

A cargo truck blow its horn and can be heard at a distance of 10.0 m with a sound intensity level 93.0 dB. If 6 identical cargo trucks simultaneously blow their horns, what combined sound intensity level can be heard at a distance of 10.0 m form these trucks?

A person wears a hearing aid that uniformly increases the intensity level of all audible frequencies of sound by 30.0 dB. If the hearing aid picks up a sound with an intensity of 3.5 x 10^-9 W/m² , what is the sound intensity delivered to the eardrum?

A bullet fired at an angle θ = 60degress with a velocity of 30 m/s.

Acceleration due to gravity is 10 m/s2. What is the time interval to

reach the maximum height?

A circular loop of wire of radius 0.25 cm is expected to an external

magnetic field that is perpendicular to the plane of the loop. For a time,

the magnetic field decreases at a rate of 0.0035 T/s. What is the

magnitude of the induced electromagnetic force in the loop?

A body of mass 10 kg and initially at rest is subjected to a force of 20N for a distance of 10m. Calculate the change in kinetic energy of the body

Two equal charges are placed 100m a part of the force of attraction between them is 0.2N,calculate the value of the two equal charges