Phase Change
Time (min) Temperature (oC)
0 15
1 32
2 45
3 48
4 54
5 54
6 54
7 54
8 54
9 59
10 60

A certain substance is a solid at 15°C. Sarah heated a sample of the solid substance in a beaker using a Bunsen burner during science class. She and her partner recorded the temperature at one-minute intervals. Their data is recorded in the table below. Based on the girls' data, when was the kinetic energy of the substance the greatest?

Which is not true about oxygen-17 and oxygen-18?

The uniform slender bar rests on a smooth horizon- tal surface when a force f is applied normal to the bar at point a. point a is observed to have an initial acceleration aa of 20 m/s2, and the bar has a corre- sponding angular acceleration of 18 rad /s2. deter- mine the distance b.

An athlete swings a ball, connected to the end of a chain, in a horizontal circle. the athlete is able to rotate the ball at the rate of 8.13 rev/s when the length of the chain is 0.600 m. when he increases the length to 0.900 m, he is able to rotate the ball only 6.04 rev/s. (a) which rate of rotation gives the greater speed for the ball? 6.04 rev/s 8.13 rev/s (b) what is the centripetal acceleration of the ball at 8.13 rev/s? m/s2 (c) what is the centripetal acceleration at 6.04 rev/s? m/s2