Why are all machines not 100% efficient

A. Mass

B. Gravity

C. Friction

D. Distance

What are some non examples of density

What is the relationship between thermal energy and friction

Rutherford proposed that ... A) the atom is mostly solid space B) the electrons are spread through a solid, positive nucleus C) electrons are located surrounding a nucleus D) atoms are the smallest particles of matter

What are the factors that effect the strength of a frictional force? the acceleration of an object the color and density of an object the buoyant forces acting on an obeject the mass of an object and how rough te surface is

What are 3 different forces that act on objects on the earth

A taxi hurries for 1 3/4 hours with a constant speed of 84 mph and then for another 1 hour 45 minutes with a constant speed of 24 mph. what is its average speed for the total trip?

A carbon atom has how many valence electrons?

X-rays UV light waves Sound waves Earthquake waves. All of these have which characteristic in common?

V=345m/s, 7210Hz, X=?

As a mercury atom absorbs a photon of energy, an electron in the atom changes from energy level d to energy level e. Determine the energy of the absorbed photon in electronvolts.