Greg walks on a straight road from his home to a convenience store 3.0 km away with a speed of 6.0 km/h. On reaching the store he finds that the store is closed, he instantly turns around and walks back with a speed of 9.0 km/h. Round your final answers to 2 significant figures. a. What is the magnitude of average velocity and average speed of Greg over the first 30 mins of his travel?

B. Find the magnitude of Greg’s average velocity and speed in the time from 0 to 50 minutes

C. Calculate the magnitude of the average velocity and speed in the first 40 minutes (between 0 and 40 mins) of the walk?

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