Name the device which converts: chemical into light

An alternating current in a wire has a voltage of 2,800 V. It needs to be reduced 70 V. The wire makes 120 turns in the primary coil of a step - down transformation. How many turns of wire need to be in the secondary coil?

A ball starts from rest. It rolls down a ramp and reaches the ground after 4 seconds. Its final velocity when it reaches the ground is 7.0 meters/second.

An object is thrown upwards with the speed of 40.0 km/hr in 5 second, calculate the distance in millimeters (mm).

Properties of matter are typically broken into two categories: physical and?

What is being transferred with a wave? A: Matter B: Medium C: Energy D: Water

A car travels 35.0 mph north for 1.00 hour, then 40.0 mph east for 0.0500 hour, and finally 50.0 mph northeast for 2.00 hours. Calculate the average speed.

A 500 lb steel beam is lifted up by a crane to a height of 100 ft and is held there. A) How much work is being done to hold the beam in place? B) How much work was done to lift the beam?

If Light is shone through the slits of a card onto a sheet of white paper describe what is seen.

When you break a magnet in half, how many poles does each piece have? Explain.

What can you use to unscrew a tiny screw?