A heat engine produces 8200 j of heat while performing 3200 of useful work. what is the efficiency of this engine? (i'm doing something wrong.)

How do scientists construct models of atoms and molecules?

Two small frogs simultaneously leap straight up from a lily pad. frog a leaps with an initial velocity of 0.551 m/s, while frog b leaps with an initial velocity of 1.75 m/s.

What light moves from a medium

A constant force of 10 N is applied to an object. The object accelerates at a constant rate of 4 m/s2. What is the mass of the object?

A car starts from rest at a stop sign. It accelerates at 4.0 m/s 2 for 6.0 s, coasts for 2.0 s, and then slows down at a rate of 3.0 m/s 2 for the next stop sign. How far apart are the stop signs?

List the different types of electromagnetic readiation (waves) in order from shortest wavelength to longest wavelength

Which way does the Coriolis effect deflect objects in the Northern Hemisphere To the south To the right To the left To the north

Let T be a linear transformation from a vector space V with dimension 11 onto a vector space W with dimension 7. What is the dimension of the nullspace of T?

What is the fundamental unit for measuring mass in the metric system?

Why are some craters on the moon bigger than others