an incandescent lightbulb has an efficiency of 2.1% and a power of 60 w. how much light energy does the lighbulb produce in 1 second

Can charge exist without having mass and occupying some volume?

A wire of length L and cross-sectional area A has resistance R. What will be the resistance Rstretched of the wire if it is stretched to twice its original length?

A baseball is traveling (=20m/s) and us hit by a bat. it leaves the bat traveling (-30 m/s). What is the change in the velocity? remember that direction is what makes velocity diffrent speed.

Why does athlete pushes the earth backward fith his feet and hands just before the race starts

What is the velocity of an object that has been in free fall for 0.10 s?

Two water manometers are connected to a tank of air. One leg of the manometer is open to 100kPa pressure (absolute) while the other leg is subjected to 90kPa. Find the difference in deflection between both manometers, Delta h_a - Delta h_b.

Most geologists believe that the dinosaurs became extinct 65 million years ago when a large comet or asteroid struck the earth, throwing up so much dust that the sun was blocked out for a period of many months. A.

If you drop a silver dollar off a building and it hits the ground in 10 seconds, how fast was the coin going just before it hit?

What is the weight of an with a mass of 32kg

The index of refraction of silicate flint glass for red light is 1.620 and for violet light is 1.660. A beam of white light in this glass strikes the glass-air interface at a 25.50∘ angle of incidence and refracts out into the air.