1. A boy moves on a skateboard at a constant velocity of 3 m-s-'. The combined mass of the boy and the skateboard is 40 kg. He catches a bag of
flour of mass 5 kg that is thrown to him horizontally at 6 m-s-!. Determine
the velocity of the boy after catching the bag of flour. (2 m-s ' in his original
direction)

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?

Oxygen undergoes an isentropic expansion from 120 degree c and 280 kpa absolute to 140 kpa absolute. determine the final temperature of the oxygen and the amount of work per kg of o_2 produced in the process if it is adiabatic.

If the new moon happens on january 15th, what shape will it be on february 6th?