Which should you NOT assume is in freefall? O A rock falling on a planet with no air
O A ball which rolled off of the table and is falling a short distance to the ground.
O A feather falling through the air
O A ball which is flying upward
O All of these are in freefall

Apiece of metal 75g at 110°c is dropped in a container with 500g at 20°c. the h2o if temperature is 24°c find specific heat capacity of metal

How do i solve this physics problem?

Lake happy times contains 100 km3 of pure water. it is fed by a river at a rate of 50 km3/yr. at time zero, there is a factory on one shore of lake happy times that begins introducing a pollutant to the lake at a rate of 2km3/yr. there is another river that is fed by lake happy times at a rate that keeps the volume of lake happy times constant. this means that the rate of flow from lake happy times into the outlet river is 52km3/yr. in turn, the flow from this outlet river goes into another lake, lake sad times, at an equal rate. finally, there is an outlet river from lake sad times flowing at a rate that keeps the volume of lake sad times at a constant 100 km3 . (a) find the amount of pollutant in lake sad times at the end of 3 months. (b) at the end of 3 months, observers close the factory due to environmental concerns and no further pollu- tant enters lake happy times. how long will it take for the pollutant in lake sad times (found in part (a)) to be cut in half?