A80 kg skier grips a moving rope that is powered by an engine and is pulled at constant speed to the top of a 25 degrees hill. the skier is pulled a distance = 220 m along the incline and it takes 2.3min to reach the top of the hill.
if the coefficient of kinetic friction between the snow and skis is = 0.15, what horsepower engine is required if 30 such skiers (max) are on the rope at one time?

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?

Atomic nuclei of almost all elements consist of

Most short-period comets do not have randomly oriented orbits because