A heat engine has a thermal efficiency of 45%. how much power does the engine produce when heat is transferred into it at a rate of 109 kj/hr?

Suppose you needed to build a raft to cross a fast-moving river. Describe the physical and chemical properties of the raft that would be important to ensure your safety.

A bag of books took 3 minutes to move. You did 12,900 J of work. How much power was required to move the bag?

A kid is on a skate board going 14kph and trows a set of keys on the ground at 8kph. the spped of the keys relitive to the gound is?

The electrostatic force of attraction between two charges, a and b, is proportional to

A 200 N force is applied to an object (that is at the origin) at 30 degrees above the horizontal on the positive x axis. A second force is applied at 20 degrees below the horizontal on the negative x axis.

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?

A pair of scissors is a complex machine. what simple machines make up a pair of scissors?

Methane gas absorbs red light, and methane clouds reflect blue light, giving Uranus and Neptune their distinctive blue colors. Why do Uranus and Neptune have methane clouds, but Jupiter and Saturn do not