A book with a mass of 950 g is placed on a shell which is 1.5 m above the ground (a * 98 N/kg) Gold Give your answer to 4 significant figures.
Change in gravitational potential energy store​

At time t=0, a particle is located at the point (3,6,9). it travels in a straight line to the point (5,2,7), has speed 8 at (3,6,9) and constant acceleration 2i−4j−2k. find an equation for the position vector of the particle.

What are similarities and differences of reflection, refraction, diffraction and absorption?

An object weigh 40n in air ,weigh 20n when submerged in water,and 30n when submerged in a liquid of unknown liquid density.what is the density of unknown of liquid?