A toaster can be considered to be a heat engine that does no work. Heat flows through the toaster coils without being transformed into mechanical energy. What is the thermal effeciency of this example of a heat engine?

a) 0.50

b) 1

c) 0

d) - 1

Which of the following is located in the stratosphere? A) Weather B) The ozone layer C) UV rays D) Birds

Which best describes the difference between internal and thermal energy? Internal energy is the total potential energy in a substance, and thermal energy is the total kinetic energy in a substance.

When an atom is in excited state emits a photon of radiation, the energy of the photon is equal to the?

Will an object with a density of 1.05 g/ml float or sink in water? Explain

A car starts from rest and reaches 20 m/s in 10 seconds. the average acceleration of the car in m/s2 is:

What would we need to know to calculate both work and power? energy, force, and time force, distance, and time force, mass, and distance mass, force, and energy

A 1.4 kg particle moves along an x axis, being propelled by a variable force directed along that axis. Its position is given by x = 3.0 m + (4.0 m/s) t + ct2 - (1.6 m/s3) t3, with x in meters and t in seconds. The factor c is a constant. At t = 3.

One reason that life as we know it is unlikely to exist on Venus is because A. the surface temperature is too high. B. the surface temperature is too low. C. the surface has too much ice covering it. D. there is no atmosphere.

An object has a kinetic energy of 275 j and a momentum of magnitude 25.0 kg · m/s. find the (a) speed and (b) mass of the object.

with the wind a driver travels 300 mies in 5 hours. The return trip against the wind take the driver 6 hours. At what rate would thedriver travel without any wind What is the rate of thew ind?