Askier starts from rest at the top of a 40.8 m hill, skis down a 30 degree incline into a valley, and continues up a 32.5 m high hill. the heights of both hills are measured from the valley floor. assume that you can neglect friction and the effect of the ski poles. how fast is the skier moving at he bottom of the valley? what is the skier's speed at the top of the next hill? do the angles of the hills affect your answers?

An inclined plane wrapped around a metal shaft is a a. lever b. screw c. pulley d. wedge

While studying chemical reactions and conservation of matter, sarah's class conducted a variety of experiments. sarah and her lab partner found the mass of a wax candle and placed the candle in a flask. the students lit the candle and let it burn to completion. all that was left was wax and charred candle wick. per their teacher's instructions, the students found the mass of the products. their data can be seen in the data table. formulate a hypothesis the students could test to explain why the experiment did not support the law of conservation of matter. a) the students could repeat the experiment using different candles; there might have been a flaw in the candle. b) the experiment should be repeatable. the students should run several trials and then take an average of the after mass in each trial. c) the students should have someone in the class check their measurement skills as they repeat the experiment. they may have made an error using the balance. d) the students should burn the candle in a container that has some type of lid so that any gas that is a product of the reaction can be contained and massed. submit

Find the magnetic field a distance r from the center of a long wire that has radius a and carries a uniform current per unit area j in the positive z direction.