A heat engine with a high-temperature reservoir at 400 k has an efficiency of 0.20. what is the maximum possible temperature of the cold reservoir?

1. Which of the following is a true statement concerning the electrostatic force and gravitational force acting on an electron and a proton in an atom? Fg > Fel Fel > Fg Fg = Fel We would need to know which atom 2.

How many significant digits are measurement 0.00210 mg?

a car speeds up from 10.0 m/s to 30.0 m/s in 5.00 s. the acceleration of the car is: A: 4.00 m/s^2 b: 6.00 m/s^2 c: 28.0 m/s^2 d: 8.00 m/s^2

A car velocity changed from 0 m/s to 40m/s in 5 seconds. What is the average acceleration of the car

All mass movements on Earth, landslides, slumps, creep, and avalanches for example, are caused by what action force? A) gravity B) inertia C) friction D) centripetal force

A solid sphere of radius R has a total charge Q distributed evenly throughout its volume. What fraction of the total charge is located inside a radius R/2?

What is Nothing. (sorry i have been wondering this for a very long time)

What is the speed of a bobsled whose distance-time graph indicates that it traveled 123m in 28s?

Eric has a mass of 80 kgkg. He is standing on a scale in an elevator that is accelerating downward at 1.7 m/s2m/s2. What is the approximate reading on the scale?

Without the force of friction, people would not be able to walk.