Lead shot weighing 810. g at 100°C is dropped into a calorimeter cup containing 350. g of water. The cup is 280. g of copper, and both the cup and the water are initially at 15°C. What is the final temperature?

The specific heat for water is 4.18J/g°C
The specific heat for copper is 0.390J/g°C
The specific heat for lead is 0.130J/g°C​

Aball with a mass of 275 g is dropped from rest, hits the floor and rebounds upward. if the ball hits the floor with a speed of 2.40 m/s and rebounds with a speed of 1.70 m/s, determine the following. (a) magnitude of the change in the ball's momentum (let up be in the positive direction.)

Electric field of the earth. the earth has a net electric charge that causes a field at points near its surface equal to 150 n> c and directed in toward the center of the earth. (a) what magnitude and sign of charge would a 60-kg human have to acquire to overcome his or her weight by the force exerted by the earth’s electric field? (b) what would be the force of repulsion between two people each with the charge calculated in part (a) and separated by a distance of 100 m? is use of the earth’s electric field a feasible means of flight? why or why not?

What is the force that opposes motion and works against the downward pull? a) friction b) gravity c) weight d) acceleration