During energy transformation, all energy systems: are

a. 100 percent efficient

b. lose energy

c. gain heat energy

d. create energy

Compare lunar and solar eclipses and answer the following questions: 1. How does a lunar eclipse happen? 2. How does a solar eclips happen? 3. Which one occurs more often?

Sound wave A delivers 2 J of energy in 2 s. Sound wave B delivers 10 J of energy in 5 s. Sound wave C delivers 2 mJ of energy in 1 ms. Rank in order, from largest to smallest, the sound powers of Pa, Pb, Pc of these three waves.

Janis lives 1.10 km away from the grocery store. janis walks to the grocery store and back three times a week. what is the total distance janis walks each week to buy groceries

How do you make cupcakes

What is 1.33Ω plus 2Ω?

A gate in an irrigation canal is constructed in the form of a trapezoid 2 m wide at the bottom, 38 m wide at the top, and 2 m high. It is placed vertically in the canal so that the water just covers the gate.

A machine with a mechanical advantage of 10 is used to produce an output force of 250 newtons. What input force is applied to this machine

Why do you float in space

How does physical change affect the identity of a substance

A scientist pours grape juice on three identical white shirts He then uses three different cleaning products on the shirts and measures how clean they get what is the independent variable in this experiment