Aconstant electric field with magnitude 1.50 ✕ 103 n/c is pointing in the positive x-direction. an electron is fired from x = −0.0200 m in the same direction as the electric field. the electron's speed has fallen by half when it reaches x = 0.170 m, a change in potential energy of 4.56 ✕ 10−17 j. the electron continues to x = −0.210 m within the constant electric field. if there's a change in potential energy of −9.12 ✕ 10−17 j as it goes from x = 0.170 m to x = −0.210 m, find the electron's speed (in m/s) at x = −0.210 m. hint notice the electron turned around at some point. when the electron's speed is half its initial value, you are given the change in electric potential energy. the sum of δu and δk at this point is a conserved quantity, and is equal to zero, so δu + δk will be the same at all points along the electron's trajectory. you are given δu at the point of interest, so write δk in terms of velocities, substitute the velocity at the second point with the initial velocity divided by 2, simplify your equation, and solve for vf.

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

The graph represents the distance a car travels over time while on the highway. which statement about the car's trip is accurate? a) the car does not move over time. b) the car travels at a constant velocity. c) the car's velocity increases constantly over time. d) the car's velocity decreases constantly over time.

What happens when you slowly pulled the carboard?