In a classroom, why can we hear the sound waves produced by the teacher talking?

How does an iron nail become a rusty nail

You are on an airplane traveling 30° south of due west at 140 m/s with respect to the air. The air is moving with a speed 35 m/s with respect to the ground due north.

Which of the following water samples would be considered acidic

Why do we need gravity?

How muck work is done using a 500 watt microwave oven for 5 minutes

The acceleration of an object is proportional to which of the following? the mass the energy of the object the inverse of the mass the inverse of the force applied

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?