1. Which of the following is an example of a second-class lever?

wheelbarrow

broom

crowbar

shovel

2. Which of the following is an example of a first-class lever?

rake

nut cracker

seesaw

elbow joint

Suppose you measure the mass of a banana before it rots. You measure the mass again days later after the banana has turned black and find that the mass is less. Use the law of conservation of mass to conclude what happened to the mass of the banana.

At one time in the Earth's history, many people thought the world was flat. Which best explains why the model of the Earth is now round? Models are limited by the science-the more that was discovered, the better the model could be made.

How can two strengths be added together

When water waves approach an obstacle such as the supports holding up a pier, they will bend around the supports. This wave phenomenon is called a. reflection. b. refraction. c. diffraction. d. polarization.

The Great Lakes of the United States are often covered with a sheet of ice every winter. Which best explains why this ice does not sink to the bottom?

A 15 kg child experiences an acceleration of 0.25 m/s2 as she is pulled 1.7 m horizontally across the floor by her sister. what is the change in the child's kinetic energy?

A piece of candy has 5 calories (or 5000 calories). if it could be burned, leaving nothing but carbon dioxide and water, how much heat would it give off?

The orientation in space of the electron is described by which quantum number?

Which statement best defines why sound waves are mechanical waves? A. They require a medium in which to travel B. They can travel through a vaccum C. They can travel only through solids D. They can travel through gases

Consider the uniform electric field E = (2.5 j + 3.5 k) * 103 N/C. (a) Calculate the electric flux through a circular area of radius 2.5 m that lies in the yz-plane. Give your answer in N·m2/C.