How many times louder is a sound wave with an intensity of 50 dB than a sound wave with an intensity of 20 dB?

What is the enthalpy change (in kj) of a chemical reaction that raises the temperature of 250.0 ml of solution having a density of 1.25 g/ml by 9.20 °c? (the specific heat of the solution is 3.74 joules/gram-k.) ?

The figure shows Atwood's machine, in which two containers are connected by a cord (of negligible mass) passing over a frictionless pulley (also of negligible mass).

One of the main reasons steel is used more widely than iron is because it's lighter softer stronger than iron

A car speeds up from 12.0 m/s to 16.0 m/s in 8.0 s. the acceleration of the car is?

A note on a piano vibrates 262 time per second. What is the period of the wave

A change from one form of energy into another is called a. gravitational potential energy. b. work. c. conservation of energy. d. an energy transformation

4. An airplane must achieve a velocity of 71 m/s for takeoff. If the runway is 1000 m long, what must the acceleration be?

As the average kinetic energy of the particles in a gas increases, which of the following occurs?

Power=170 watts time=20 seconds

What is the charge of alpha, beta and gamma rays?