7. A 10-kg block on a horizontal frictionless surface is attached to a light spring (force constant = 0.80 kN/m). The block is initially at rest at its equilibrium position when a force (magnitude P =
80 N) acting parallel to the surface is applied to the block, as shown. What is the speed of the
block when it is 13 cm from its equilibrium position?
P
00000000
a.
b.
0.85 m/s
0.89 m/s
0.77 m/s
0.64 m/s
0.52 m/s
d.
e.

Which force is most responsible for binding together an atom's protons and neutrons? electrostatic gravitational nuclear magnetic

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 objects of different mass start from rest, are pulled by the same magnitude net force, and are moved through the same distance. the work done on object 1 is 900 j. after the force has pulled each object, object 1 moves twice as fast as object 2. how much work is done on object 2?