Use the following picture to answer questions #17 and #18. Consider that after t
ID: 1794684 • Letter: U
Question
Use the following picture to answer questions #17 and #18. Consider that after the snowboarder starts down from the hill from point A, she travels all the way to the end of the path. 17. Standing still at the top of the hill at point A, what kind of energy (potential and/or kinetic) would the snowboarder have? How do you know? 18. Explain the energy conversion from point C to point 8. Make sure to include a description of both kinetic and potential energy 19. A small dog is trained to jump straight up a distance of 1.2 m. How much kinetic energy does the 7.2- kg dog need to jump this high? (The acceleration due to gravity is 9.8 m/s2.) Show your work for credit 20. As 390 g of hot milk cools in a mug, it transfers 30,000 J of heat to the environment. What is the temperature change of the milk? The specific heat of milk is 3.9 1/g "C. Show your work for credit. 21. Thermal conductors don't have to be hot to transfer heat. According to Ch.16, explain a situation when an ice cube would still transfer heat to another object it is in contact with. Copyr©2015by James Madison High School, Norcross GA ieserved Ne part of his publication may be reproduced, distributed, or transmited in any form or by nny mcns, incloding r odher electrmnic or mechanical methods, without the prior writen permission of the publisher photocopying reoceding.ceExplanation / Answer
17. POtential energy.
(it is at rest at A so Kinetic energy will be zero.)
and A is at some height above the B and C so it will more potential than B and C.
18. PEc + KEc = PE b + KE b
taking c at zero height level and b is h height above b then
0 + m Vc^2 /2 = m g h + m vb^2 / 2
19. PEi + KEi = PEf + KEf
0 + m v^2 /2 = mg h + 0
v = sqrt(2 x 9.8 x 1.2) = 4.85 m/s