Ablock with mass m1 = 4.50 kg and a ball with mass m2 = 7.70 kg are connected by a light string that passes over a frictionless pulley, as shown in figure (a). the coefficient of kinetic friction between the block and the surface is 0.300.  (a) find the acceleration of the two objects and the tension in the string.  (b) check the answer for the acceleration by using the system approach. (use the following as necessary: m1, m2, μk, and g.)  (c) what if an additional mass is attached to the ball? how large must this mass be to increase the downward acceleration by 60%?   for (a) i calculated acceleration to be 5.10 m/s^2 and tension to be 36.2n.  for (b) i the equation is a = (m2g-ukm1g)/(m1+m2)  it is (c) that i cannot figure out. can anybody me?

Why should seat belts not be mandatory quick plz

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

Acar drives toward the right over the top of a hill, as shown below. which arrow represents the centripetal acceleration? w x y z