Does friction depends on the nature of two syrfaces which are in contact with each other

Whats the rounded Atomic mass of iron?

An area of 1.00 x 10^2cm^2 is how many square meter

A body will maintain a constant negative electrostatic charge if the body A) maintains the excess of electrons B) continously receives more protons than it loses C) continuously receives more electrons than it loses D) maintains the same excess of

How fast do you need to swing a 250-g ball at the end of a string in a horizontal circle of 0.6-m radius so that the string makes a 39 degree angle relative to the horizontal?

A jet has amass of 40,000 kg. The thrust for each of the four engines is 20,000 N. What is the jet's acceleration?

How does the direction of acceleration compare with the direction of the net force that produces it

17. Elaine connects an ammeter to a lamp, which is connected to a battery. She records the current. She connects another battery in series to the circuit and records the ammeter reading again. She repeats this step two more times.

If you have two different sized velocity vectors representing two objects moving in the same direction, then what can you conclude?

The identity of an element depends on the number of 1. protons in the atom. 2. electrons in the atom. 3. neutrons in the atom. 4. protons and neutrons in the nucleus.

Why do the positions of stars change in the universe?