An athlete at the gym holds a 2.5 kg steel ball in his hand. His arm is 70 cm long and has a mass of 4.0 kg. a) What is the magnitude of the torque about his shoulder if he holds his arm straight out to his side, parallel to the floor?
b) What is the magnitude of the torque about his shoulder if he holds his arm straight, but 55? below horizontal?

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?

Acar moves a distance of 50.0 km west, followed by a distance of 64.9 km north what was the magnitude of the displacement of the car, in units of kilometers?

Ameter stick is pivoted at the 0.50-m line. a 3.0-kg object is hung from the 0.15-m line. where should a 5.0-kg object be hung to achieve equilibrium (the meter stick oriented horizontal and motionless)?