An object travels from a point X to another point Y in 10 s. The distance between them is 30 m. It travels again from Y to Z and covers 40 m. The average speed of the object during the whole journey is 2 m/s. How long the object takes to travel from Y to Z?​

If a refrigerator is a heat pump that follows the first law of thermodynamics, how much heat was removed from food inside of the refrigerator if it released 380j of energy to the room?

Achlorine atom has 17 protons and 18 neutrons. what is its mass number? what is its atomic number?

Choose a realistic problem for which these are the correct freebody diagrams. be sure that the answer that the problem requests is consistent with the diagrams shown. choose a realistic problem for which these are the correct freebody diagrams. be sure that the answer that the problem requests is consistent with the diagrams shown. a 1.0 kg block is placed on top of a 2.0 kg block. a horizontal rope pulls the 2.0 kg block across a frictionless floor with a force of 21.0 n. the coefficient between the two blocks is 0.75. does the 1.0 kg block on top slide?