Why matter has mass

A wagon is being pushed eastward with a force of 80n. the frictional force opposing the motion is 35n west. the wagon experiences a 60n gravitational force pulling downward. the ground counteracts that force with a normal force pushing upward.

Only a small amount of the energy used in an incandescent light bulb (regular bulbs commonly used in households) is actually converted into light. What happens to the rest of the energy

A spring has a natural length of 20cm. If a 25-N force is required to keep it stretched to a length of 30 cm, how much work is required to stretch it from 20 cm to 25 cm?

When tightening a bolt, you push perpendicularly on a wrench with a force of 170 N at a distance of 0.155 m from the center of the bolt.

Auroras occur in the what atmosphere

For glass fragments to be individualized, what must be true? A. They must fit together B. They must have the same density C. They must look the same D. They must be the same color

In what way would a digital thermometer be preferable to those from a liquid-based thermometer? Digital thermometer readings are easier to use when performing calculations.

Why does the core of the sun contain more helium and less hydrogen than the surface of the sun?

What happens to a light ray passing through the center of a lens?

A spider crawling across a table leaps onto a magazine blocking its path. The initial velocity of the spider is 0.870 m/s at an angle of 35.0° above the table, and it lands on the magazine 0.0770s after leaving the table. Ignore air resistance.