How many substances/elements are on the periodic table?

A gust of wind blows an apple from a tree. As the apple falls, the force of gravity on the apple is 9.39 N downward, and the force of the wind on the apple is 1.54 N to the right. What is the magnitude of the net external force on the apple?

Which considerations are used to calculate a windchill factor?

A train travels 140 km in 2 hours and 30 minutes. What is its average speed?

The average rate of disappearance of ozone in the reaction is

How is it possible to be accelerating and traveling at a constant speed?

Suppose you squeeze a sponge into a small ball. does the mass of the sponge change? Does it's density change?

A solid round bar with diameter of 2-in has a groove cut to a diameter of 1.8-in, with a groove radius of 0.1-in. the bar is not rotating.

If a pilot pulls her 12.0 kg rollaboard suitcase along the ground with a force of 25. N for 10 M. The handle she pulls on makes an angle of 36.5 degrees with the horizontal. How much work does she do over the ten meter distance?

What happens to the density when water is poured into a empty glass?

A British newspaper was interested in whether groups of people who differed in social standing were treated differently when they complained to organizations about poor service they had received.