1. A soccer ball and a bowling ball have a head-on collision at this instant. Rolling friction is negligible.
2. | A weightlifter stands up at constant speed from a squatting position while holding a heavy barbell across his shoulders.
3. | A steel cable with mass is lifting a girder. The girder is speeding up:

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?

How is the gravitational force related to the distance between two objects?

What is the coefficient of kinetic friction μk between the block and the tabletop?