Single – Theory
Objective:
Date: _____________
Conservation of Energy III
Homework: TBD
AP Physics “B”
Mr. Mirro
Date: ________
Conservation of Energy III
Ex 1: A cable lifts a 1200 kg elevator at a constant velocity for a distance of 35 m. What is the work
done by (a) the tension in the cable and (b) the elevator’s weight ? [CutnellP6.68]
Ex 2: A 10 kg mass is moving at 5 m/s over a rough surface. A 50 N horizontal tension force
causes it to accelerate to 8 m/s while traveling 6 m. Find the coefficient of kinetic friction.
[Mooney4.7]
Ex 3: A ball, starting from point A in the diagram, is projected down the curved runway. Upon leaving
the runway at point B, the particle is traveling straight upward and reaches a height of 4 m above
the floor before falling back down. Ignoring friction and air resistance, find the speed of the
particle at point A. [CutnellP6.77]
Ex 4: One of the fastest roller coasters in the world is the Magnum XL-200 at Cedar Point Park
in Sandusky, Ohio. The ride includes a vertical drop that accelerates the cart to a speed of
34 m/s [76 mi/hr] at the bottom of the dip. Assume that the coaster has a speed of nearly
zero as it crests the top to the hill. Neglecting friction and other non-conservative forces,
determine the approximate height of the peak. [Cutnell6.10sim]
[Hint: Use an energy approach]