What is the density of an object that has a mass of 20kg and a volume of 4ml?

Can anybody me with this? ? (picture included.)

Ryan is examining the energy of the particles in a bar of gold. what is ryan most likely studying?

To practice problem-solving strategy 10.1 for energy conservation problems. a sled is being held at rest on a slope that makes an angle θ with the horizontal. after the sled is released, it slides a distance d1 down the slope and then covers the distance d2 along the horizontal terrain before stopping. find the coefficient of kinetic friction μk between the sled and the ground, assuming that it is constant throughout the trip.