WWW.MIAMI-BEST-MATH-TUTOR.COM PAGE 1 OF 12 PRACTICE PROBLEMS SET 2.1 WWW.MIAMI-BEST-MATH-TUTOR.COM E-MAIL: MIAMIMATHTUTOR@GMAIL.COM CONTACT NUMBER: (786)556-4839 1. A child does 350 J of work while pulling a box from the ground up to his tree house with a rope. The tree house is 6.9 m above the ground. What is the mass of the box? a 4.7 kg b 3.1 kg c 5.2 kg d 5.2 kg
2. A futuristic design for a car is to have disk-like flywheel within the car storing kinetic energy. The flywheel has mass 370 kg with a radius of 0.50 m and can rotate up to 340 rev/s. Assuming all of this stored kinetic energy could be transferred to the linear velocity of the 3200-kg car, find the maximum attainable speed of the car. WWW.MIAMI-BEST-MATH-TUTOR.COM PAGE 2 OF 12
3. A pitcher is employing a ballistic pendulum to determine the speed of his fastball. A 5.3 kg lump of clay is suspended from a cord 2.0 m long. When the pitcher throws his fastball aimed at the clay, the ball becomes embedded in the clay and the two swing up to a maximum height of 0.10 m. If the mass of the baseball is 0.21 kg, use conservation of momentum and energy to find the speed of the pitch. WWW.MIAMI-BEST-MATH-TUTOR.COM PAGE 3 OF 12
4. A 12.0-g rifle bullet is fired with a speed of 762 m/s into a ballistic pendulum with mass 6.00 kg, suspended from a cord 70.0 cm long. Compute the vertical height through which the pendulum rises; the initial kinetic energy of the bullet and pendulum immediately after the bullet becomes embedded in the pendulum. WWW.MIAMI-BEST-MATH-TUTOR.COM PAGE 4 OF 12
WWW.MIAMI-BEST-MATH-TUTOR.COM PAGE 5 OF 12 5. A rifle bullet with mass 8.00 g strikes and embeds itself in a block with mass 0.992 kg that rests on a frictionless, horizontal surface and is attached to a coil spring. The impact compresses the spring 15.0 cm. Calibration of the spring shows that a force of 0.750 N is required to compress the spring 0.250 cm. Find the magnitude of the block s velocity just after impact. What was the initial speed of the bullet?
6. A 5.00-g bullet is shot through a 1.00-kg block suspended on a string 2.000 m long. The center of mass of the block rises a distance of 0.45 cm. Find the speed of the bullet as it emerges from the block if its initial speed is 450 m/s. WWW.MIAMI-BEST-MATH-TUTOR.COM PAGE 6 OF 12
7. A 5.00-g bullet is fired horizontally into a 1.20 kg wooden block resting on a horizontal surface. The coefficient of friction between the surface and the block is 0.200. The bullet remains embedded in the block, which is observed to slide 0.230 m along the surface before stopping. What was the initial speed of the bullet? WWW.MIAMI-BEST-MATH-TUTOR.COM PAGE 7 OF 12
8. You have just landed on Planet Y where the acceleration due to gravity is different from Earth. You take out a basketball that weights 14.7 N on the surface of Earth, release from rest form a height of 10.0 m, and measure that it takes 2.6 s to reach the ground. How much does the ball weigh on the surface of Planet Y? WWW.MIAMI-BEST-MATH-TUTOR.COM PAGE 8 OF 12
WWW.MIAMI-BEST-MATH-TUTOR.COM PAGE 9 OF 12 9. A force in the +y direction applied at the point gives rise to a torque of 56 N m about the origin. Find the magnitude of the force. a 40 N b 56 N c 67 N d 24 N
WWW.MIAMI-BEST-MATH-TUTOR.COM PAGE 10 OF 12 10. A wheel accelerates from rest to 59 rad/s at a rate of 24 rad. Through what angle (in radians) did the wheel turn while accelerating? a 59 rad b 146 rad c 73 rad d 92 rad
WWW.MIAMI-BEST-MATH-TUTOR.COM PAGE 11 OF 12 11. In a shuffleboard game, the puck slides a total of 12 m before coming to rest. If the coefficient of kinetic friction between the puck and board is 0.25, what was the initial speed of the puck? a 6.9 m/s b 30.7 m/s c 7.7 m/s d 6.2 m/s
WWW.MIAMI-BEST-MATH-TUTOR.COM PAGE 12 OF 12 12. Two paint buckets of mass 12.0 kg and 4.0 kg are connected by a lightweight rope passing over a pulley of negligible mass and friction. The system is released from rest with the 12.0 kg bucket 2.00 m above the floor. Use energy conservation to find the speed with which this bucket strikes the floor. 2.00 m