Me !
mr. nakamora wants to test the accuracy of an old balance in his classroom compared to a brand-new balance that he knows is accurate. he weighs an object on the old balance and finds it to have a mass of 15.6 grams. the same object weighs 15.9 grams on the brand-new balance.

what is the percent error between the old and new balance?

a) 0.97%
b) 1.29%
c) 1.89%
d) 2.29%

Diamond will scratch quartz. true or false

5g of ammonium nitrate was dissolved in 60g of water in an insulated container. the temperature at the start of the reaction was 23.0°c and at the end it was 19.0°c. calculate the energy absorbed by the reaction.

Aball is thrown from the top of a building with an initial velocity of 21.9 m/s straight upward, at an initial height of 51.6 m above the ground. the ball just misses the edge of the roof on its way down, as shown in the figure. (a) determine the time needed for the ball to reach its maximum height. (b) determine the maximum height. (c) determine the time needed for the ball to return to the height from which it was thrown, and the velocity of the ball at that instant. (d) determine the time needed for the ball to reach the ground. (e) determine the velocity and position of the ball at t = 5.35 s.