012 (part 1 of 2) 10.0 points A runner is jogging in a straight line at a

steady v = 4.6 km/hr. When the runner is

L= 3 km from the finish line, a bird begins

flying straight from the runner to the finish

line at vý= 9.2 km/hr (2 times as fast as the

runner). When the bird reaches the finish

line, it turns around and flies direztly back to

the runner.

Yvette hangs a 2.4kg bird feeder in the middle of a rope tied between two trees. the feeder creates a tension of 480 n in each side of the the rope.

Asolid cylinder and a cylindrical shell have the same mass, same radius, and turn on frictionless, horizontal axles. the cylindrical shell has light-weight spokes connecting the shell to the axle. a rope is wrapped around each cylinder and tied to blocks of equal masses that are held the same height above the ground. both blocks are released simultaneously. the ropes do not slip. which block hits the ground first? or is it a tie?

How many milliliters of water at 23 °c with a density of 1.00 g/ml must be mixed with 180 ml (about 6 oz) of coffee at 95 °c so that the resulting combination will have a temperature of 60 °c? assume that coffee and water have the same density and the same specific heat. how much will the temperature of a cup (180 g) of coffee at 95 °c be reduced when a 45 g silver spoon (specific heat 0.24 j/g °c) at 25 °c is placed in the coffee and the two are allowed to reach the same temperature? assume that the coffee has the same density and specific heat as water. a 45-g aluminum spoon (specific heat 0.88 j/g °c) at 24 °c is placed in 180 ml (180 g) of coffee at 85 °c and the temperature of the two become equal. (a) what is the final temperature when the two become equal? assume that coffee has the same specific heat as water. (b) the first time a student solved this problem she got an answer of 88 °c. explain why this is clearly an incorrect answer.