Arock is rolling down a hill. at position 1, its velocity is 2.0 m/s. twelve seconds later, as it passes position 2, its velocity is 44.0 m/s. what is the acceleration of the rock? 42.0 m/s
2 3.7 m/s2
3.8 m/s2
3.5 m/s2

An ideal spring has a spring constant (force constant) of 2500 n/m, is stretched 4.0 cm, how much elastic potential energy does it possess? (a) 3j (b) 0.00j (c) 1j (d) 2j (e) 4j

Which of the following statement is false ? a.batteries should never be stored on metal trays or outside in the elements)b, battery acid cannot be neutralized)c.do not stack batteries on top of each other)d.never put a damaged battery in a dumpster. i

Two point charges lie on the x axis. a charge of + 2.30 pc is at the origin, and a charge of − 4.50 pc is at x=−11.0cm. what third charge should be placed at x=+26cm so that the total electric field at x=+13.0cm is zero? express your answer to three significant figures and include appropriate units.