The drawing shows a model for the motion of the human forearm in throwing a dart. because of the force m applied by the triceps muscle, the forearm can rotate about an axis at the elbow joint. assume that the forearm has the dimensions shown in the drawing and a moment of inertia of 0.065 kg . m2 (including the effect of the dart) relative to the axis at the elbow. assume also that the force m acts perpendicular to the forearm. ignoring the effect of gravity and any frictional forces, determine the magnitude of the force m needed to give the dart a tangential speed of 5.0 m/s in 0.10 s. starting from rest.

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