The acceleration of a rocket fired vertically upwards t seconds after launch is 20+2t ms−2 (as a rocket burns fuel it becomes lighter, so accelerates more quickly). What is the second order differential equation for the height of the rocket. h′′= What is the general solution? (Please use A as the first constant of integration and B as the second): General solution: h = Use the fact that at t = 0 the rocket was on the ground and not moving to find the particular solution that gives the height of the rocket. How high was the rocket after 10 seconds? How fast was it moving then? (hint: acceleration is the rate of change of velocity. The velocity of the rocket is the rate of change of what?)

Amass has an acceleration of 10- 2t. what is its velocity and displacement if it started at x- 4m and the initial velocity was 8m/s? at what time does it have 0 velocity? graph all graphs.

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

Two forces produce equal torques on a door about the door hinge. the first force is applied at the midpoint of the door; the second force is applied at the doorknob. both forces are applied perpendicular to the door. which force has a greater magnitude?