physics- PLEASE HELP
posted by kim on .
2. A .12 kg ball is moving at 6 m/s when it is hit by a bat, causing it to reverse direction and have a speed of 14 m/s. What is the change in the magnitude of the momentum of the ball?
4. Lonnie pitches a baseball of mass .2 kg. The ball arrives at home plate with a speed of 40 m/s and is batted straight back to Lonnie with a return speed of 60 m/s. If the bat is in contact with the ball for .050 s, what is the impulse experienced by the ball?
2. Although the momentum changes by 0.12 kg * [6 -(-14)m/s]= 2.4 kg m/s, becasue the direction reverses, the MAGNITUDE of the momentum changes only by 0.12 kg*(14 - 6)m/s = 0.72 kg m/s
4. Compute the momentum change, taking into account the direction change. That will equal the impulse. Divide that by the time interval of contact to get the average force.