A 30w light bulb uses 600J of electrical energy in a certain period of time. In that time, it produces 450 J of light energy. The rest of the energy is wasted calculate the efficiency of the light bulb

Calculate the acceleration if you push with a 20-N horizontal force against a 2-kg block on a horizontal friction - free air table

Forces of attraction between particles is the smallest in gas solid and liquid liquid solid

What would happen to the stratosphere if humans were to increase the amount of ozone within it?

When resistors 1 and 2 are connected in series, the equivalent resistance is 14.9 ω. when they are connected in parallel, the equivalent resistance is 2.69 ω. what are (a) the smaller resistance and (b) the larger resistance of these two resistors?

A guarded barbed wire fence separates east and west bovinia. soccer players are paid twice as much in west bovinia as in east bovinia. this is an example of

A constant tone is being applied to a speaker. The voltage across the speaker is 5 volts. The voltage across the speaker is increased to 15 volts in order to increase the sound level. What is the decibel gain, rounded to the nearest decibel?

When is the average velocity equal to the instantaneous velocity

Tightening a screw with a larger spacing between its threads requires fewer turns of a screwdriver than tightening a screw with smaller thread spacing. What is a disadvantage of the screw with larger thread spacing?

The role of plants in the water, oxygen, nitrogen, and carbon cycles

As pitch gets higher, wavelength gets?