University:
University of Colorado Boulder
Course:
PHYS 2010 | General Physics 1
Academic year:

2021
Views:

373

Pages:

2
Author:

aulalegirm5yr

re - Y-£may / Name: Work, Energy, and Power Work- Energy Calculations and Power chapter at The Physics Classroom: Study Lesson 2 of the Work, /u bc.html http://www.physicsclassroom.com/CIass/energy512 For the following questions, begin with the work -energy equation, cancel terms, substitute and solve. 1. A glider is gliding through the air at a height of 416 meters with a speed of 45.2 m / s. The glider dives to a height of 278 meters. Determine the gliders new speed . KEj PEi + / rfext + 4 (4 5 . 5 f I- KEf ' Vi = 1v 1 (y f ) k&VHs ) (asYinBrvv) A box with mass nv is sliding along on a friction free surface at 9.87 m / s at a height of 1.81 m . It travels down the hill and then up another hill a . Find the speed at the bottom of the hill . 2. 9.87 m/s St PEf + - , KEj 1 1m * + PEj KEf + V) + = + i (°1 A1 - ^ ( ' } )( d b. Find the maximum vertical height to which the box will rise on the opposite hill. KEi + X a ( n . U) 3. JBC + sf - ‘ 1 h^- lo. ftfli* ) ~ + PEf ^ A 1423 kg car is moving along a level highway with a speed of 26. m / s. The driver takes the foot off the accelerator and the car experiences a retarding force of 901 N over a distance of 106 m Determine the speed of the car after traveling this distance. - . - KEj + + - 4. jrff Wexl ^ Dl A sledder starts from rest atop a 5.0- m high hill ( A ). She sleds to the bottom and up to the top of the adjacent 3.0-m high hill. How fast is the sledder going at point B? Ignore friction. = KEf + PEf + PEj + - i (V*) + The Physics Classroom, 2009 KEf Wext KM - ( I 43& + ~ V d A B 5.0 m 3.0 m i Page 1 Work, Energy, and Power 5. A 4768- kg roller coaster train full of riders approaches the loading dock at a speed of 17.1 m / s. It is abruptly decelerated to a speed of 2.2 m / s over a distance of 13.6 m . Determine the retarding force that acts upon the roller coaster cars. KEi 6. F X, 8. i + KFf + - F - A catchers mitt recoils a distance of 12.9 cm in bringing a 142-gram baseball to a stop. If the applied force is 588 N, then what was the speed of the baseball at the moment of contact with the catcher s mitt ? KEi 7. + ^ YAF n + Wext + KEf PEf 07 ~ - a,a. ^|s ] ^ ^^ n unknown force is applied to a 12JCg mass. Tl f ce acts at Fangio of 30 degrees above the horizontal. Determirfe the force acting if the force acts for a horizontal displacement of 22 meters x and increases 2 kg mass's spe d from ll /n / s to 2 m/s: ^ ' j ttaJ KEj ^ Ei ^ + ^ ^ Wext + KEf + PEf - A physics teacher exerts a force upon a 3.29 kg pile of snow to both lift it and set it into motion. The snow leaves the shovel with a speed of 2.94 m / s at a height of 0.562 m. Determine the work done upon the pile of snow. *T j + Wext + = KEf PEf VO 9. - A 250. gram cart starts from rest and rolls down an inclined plane from a height of 0.541 m . Determine its speed at a height of 0,127 m above the bottom of the incline. + PEi + KEf ^ ( . 3.50 + PEf - -i ~ yWs . |v - a \ 10. A 4357-kg roller coaster car starts from rest at the top of a 36.5-m high track . Determine the speed of the car at the top of a loop that is 10.8 m high. M (4 PEf + ^1 &£)( * ~ ' KEf ^ )( 3(0.6 r \r - ® The Physics Classroom, 2009 + ) * + PEf JL ^ Page 2