In the figure above, an object of mass M = 2.1 kg is dropped from a distance h = 0.43 meter above an uncompressed spring. The spring has a constant of k = 210 N/m. The object becomes attached to the spring upon collision. (a)  Calculate the speed of the object when it collides with the spring.

(b)  Determine how far the spring has moved when the object reaches maximum speed.

(c)   On the grid below make a graph of the acceleration a of the block as a function of time t for two oscillations. The horizontal axis is scaled for the values of time T and 2T where T is the period of oscillation. Let t = 0 when the object is at its lowest position.

(d)  On the grid below make a graph of the kinetic energy K of the block as a function of time t for two oscillations. The horizontal axis is scaled for the values of time T and 2T where T is the period of oscillation. Let t = 0 when the object is at its lowest position.

(e)  Describe how the period of oscillation of the object could be changed to one-half its current value. Explain your reasoning.

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

**urgent** roberto plans to use two transformers to reduce a voltage of 120 v to 4 v. he uses a transformer that has 300 coils in the primary winding and 50 coils in the secondary winding. he has four other transformers, as listed in the table. which transformer should roberto use to have an ending voltage of 4 v? a- w b-xc- yd- z

Argon, neon, and xenon are examples of