Question

#4-7

Two ice skaters stand facing each other at rest on a frozen pond. They push off against one another and the 48 kg skater acquires a speed of 0.69 m/s If the other skater acquires a speed of 0.81 m/s, what is her mass in kilograms? kg My Notes Ask Your Teacher -/2 points HAFColPhys1 8.2WA019. O5 Submissiens Used A man holding a rock sits on a sled that is sliding across a frozen lake (negligible friction) with a speed of 0.510 m/s. The total mass of the sled, man, and rock is 94.5 kg. The mass of the rock is 0.280 kg and the man can throw it with a speed of 14.5 m/s. Both speeds are relative to the ground. Determine the speed of the sled (in m/s) if the man throws the rock forward (i.e., in the direction the sled is moving). m/s Determine the speed of the sled (in m/s) if the man throws the rock directly backward. m/s My Notes HAFColPhys1 8.3.WA.022 O6 Submissions Used Ask Your Teacher 1 points Two football players collide head-on in midair while chasing a pass. The first player has a 105.0 kg mass and an initial velocity of 4.50 m/s, while the second player has a 118 kg mass and initial velocity of -3.4 m/s. What is their velocity (in m/s) just after impact if they cling together? (Indicate the direction with the sign of your answer.) m/s 7. O4 points HAFColPhys1 8.3WA.024 0/6 Submissions Used My Notes Ask Your Teacher A thin block of soft wood with a mass of 0.082 kg rests on a horizontal frictionless surface. A bullet with a mass of 4.67 g is fired with a speed of 597 m/s at a block of wood and passes completely through it. The speed of the block is 17 m/s immediately after the bullet exits the block. Determine the speed (in m/s) of the bullet as it exits the block. m/s )Determine if the final kinetic energy of this system (block and bullet) is equal to, less than, or greater than the initial kinetic energy. o equal to the initial kinetic energy o less than the initial kinetic energy o greater than the initial kinetic energy Verify your answer to part (b) by calculating the initial and energies of the system in joules. inetic K,

Answer 1

given mi= 48 kg V = 0.69m/s V2 = 0.81 m/s Homentin of Momentum of Skater I - skater 2 mini =ma V2 m=mv - 48(0.69) 0.81 = 140.88 read Kg = ulkg (two significant figures)