A heat engine has a hot reservoir of 680°C and a cold reservoir of 220°C. What is the efficiency of the engine?

The Earth's magnetic field Select one: a. has flipped its North and South pole directions numerous times b. controls the orbit of the Moon c. is generated by The Sun d. has remained constant since it was first created

What was the hottest temperature ever recorded on earth?

Which of the following is a U. S. unit of measurement? A. Kelvin B. Yard C. Liter D. Meter

What equivalency exists between solid volume and liquid volume

Two cars approach each other; both cars are moving westward, one at 71 km/h, the other at 67 km/h. What is the magnitude of the velocity of the first car relative to (in the frame of reference of) the second car? Answer in units of km/h.

An ambulance is traveling east at 51.6 m/s. Behind it there is a car traveling along the same direction at 32.3 m/s. The ambulance driver hears his siren at a frequency of 615 Hz. 32.3 m/s Car 51.

When a chemical reaction occurs with only one substance, what happens to the atoms of that substance?

Total energy input is 1400 and my efficiency is 80% so what is the useful energy output in jules?

Which group of elements loses 1 electron easily?

What evidence can you cite for the particle nature of light? 1. Refraction phenomenon of light 2. The many colors of light 3. Diffraction phenomenon of light