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

What is the wavelength of a sound Wave moving at 340 mls with a Frequency of 256Hz?

How would you describe the two projectors used to screen a 3D movie? A) Both projectors have vertical polarizers. B) One projector has a vertical polarizer and the other has a horizontal polarizer. C) Both projectors have horizontal polarizers.

A cannonball is fired horizontally from the top of a cliff. the cannon is at height h = 80.0 m above ground level, and the ball is fired with initial horizontal speed v0. assume acceleration due to gravity to be g = 9.80 m/s2.

Identify each of the following statements is characteristic of series circuits parallel circuits or both: a. Current = Voltage : Resistance b. total resistance increases as more light bulbs are added c.

The current in a long wire creates a magnetic field in the region around the wire. How is the strength of that field at a given distance, r, r from the wire center related to the magnitude of the field

How much heat is contained in 100 kg of water at 60.0 °C?

Which of the following statements is the best definition of weather? Weather is the current conditions in the atmosphere. Weather is the usual conditions in the atmosphere. Weather is the average conditions in the atmosphere.

Analyze: In the series circuit what characteristic was common throughout the experiment? What changed as you added more light bulbs?

StA A boat takes off from the dock at 2.5 m/s and speeds up at 4.2 m/s2 for 6.0 s. How far has the boat traveled? Round your answer to the nearest whole number.

In Part A, you determined that the heat added to the coffee is what you got. If it takes 4.2 J of energy to raise the temperature of 1.0 mL of coffee by 1.0∘C, then it should take twice as much energy to raise the temperature of 2.