True or False:
Less power is required while lifting a box up quickly than while slowly lifting it.
A source of energy is required to do work.
Without friction or work by an external force, the sum of the potential and kinetic energies of a body is constant.
Work cannot be done in the absence of motion.
Energy conservation law for a projectile (no friction): Potential energy increase equals the kinetic energy decrease.
Work is done when the form of energy changes.

The particles of an ice cube at 0°c (represented by the blue circles) come in contact with the particles of juan’s hand at 37°c (represented by the orange circles). which diagram correctly represents the temperature of the two substances and the direction of heat flow?

The energy released by a chemical reaction can be measured using a calorimeter. when barium hydroxide octahydrate crystals are reacted with dry ammonium chloride inside of a coffee cup calorimeter, the temperature of the 18.00 g of water in the calorimeter decreases from 30.0°c to 8.0°c. the equation for calculating energy absorbed or released by a reaction is: where q is the energy released or absorbed, m is the mass of water in the calorimeter, cp is the specific heat of water, and δt is the observed temperature change. if the specific heat of liquid water is 4.19 j/g·°c, how much energy was absorbed by the reaction?

Choose all the answers that apply. our solar system: is in a spiral galaxy no longer includes pluto is made mostly of empty space is in the andromeda galaxy is the only known system that supports life