IV. More practice with momentum and collisions A. A skater of mass 45.0 kg standing on...

IV. More practice with momentum and collisions A. A skater of mass 45.0 kg standing on ice throws a stone of mass 7.65 kg with a speed of 20.9 m/s in a horizontal direction. Find: 1. The speed of the skater after throwing the stone. 2. The distance over which the skater will move in the opposite direction if the coefficient of kinetic friction between his skates and the ice is 0.03. Include an energy bar chart in your solution. B. A tall man walking at 1.25 m/s accidentally bumps his head of mass 2.95 kg on a steel doorframe. His head stops in 0.011 s. 1. What is the magnitude of the average force exerted by the doorframe on the man's head? 2. Explain why putting padding on the doorframe would help reduce this force.

Expert Solution

genius_generous answered 22 hours ago

A 45.0-kg girl is standing on a 152-kg plank. The plank, originally at rest, is free...

A 45.0-kg girl is standing on a 152-kg plank. The plank, originally at rest, is free to slide on a frozen lake, which is a flat, frictionless surface. The girl begins to walk along the plank at a constant velocity of 1.55 m/s to the right relative to the plank. (Let the direction the girl is moving in be positive. Indicate the direction with the sign of your answer.) (a) What is her velocity relative to the surface of ice?...

A 45.0-kg girl is standing on a 159-kg plank. The plank, originally at rest, is free...

A 45.0-kg girl is standing on a 159-kg plank. The plank, originally at rest, is free to slide on a frozen lake, which is a flat, frictionless surface. The girl begins to walk along the plank at a constant velocity of 1.58 m/s to the right relative to the plank. (Let the direction the girl is moving in be positive. Indicate the direction with the sign of your answer.) (a) What is her velocity relative to the surface of ice?...

Two ice skaters, Daniel (mass = 65.0 kg) and Rebecca (mass = 45.0 kg) are practicing...

Two ice skaters, Daniel (mass = 65.0 kg) and Rebecca (mass = 45.0 kg) are practicing on the ice. Daniel stops to tie his lace, and while at rest he is struck by Rebecca, who is moving 12.0 m/s before she collides with him. After the collision, Rebecca is moving forward at 8.50 m/s at a 53 degree angle with respect to her initial direction. What is the velocity vector (magnitude and direction, or x- and y-components) of Daniel after...

Mahmut with mass 70.0 kg and Güllü with mass 45.0 kg are skating. While Mahmut stands...

Mahmut with mass 70.0 kg and Güllü with mass 45.0 kg are skating. While Mahmut stands at rest, He is struck by Güllü. She is moving at 15.0 m/s before she collides with him. Güllü has a velocity of magnitude 10.00 m/s at an angle of 55.0 ∘ from her initial direction after the collision. Both skaters move on the frictionless and horizontal surface . a)Find the magnitude of Mahmut's velocity after the collision? b)Find the direction of Mahmut's velocity...

Daniel with mass 65.0 kg and Rebecca with mass 45.0 kg are skating. While Daniel stands...

Daniel with mass 65.0 kg and Rebecca with mass 45.0 kg are skating. While Daniel stands at rest, He is struck by Rebecca. She is moving at 13.0 m/s before she collides with him. Rebecca has a velocity of magnitude 6.00 m/s at an angle of 55.1 ∘ from her initial direction after the collision. Both skaters move on the frictionless and horizontal surface . a)Find the magnitude of Daniel's velocity after the collision? b)Find the direction of Daniel's velocity...

Two ice skaters, Daniel (mass 65.0 kg ) and Rebecca (mass 45.0 kg ), are practicing....

Two ice skaters, Daniel (mass 65.0 kg ) and Rebecca (mass 45.0 kg ), are practicing. Daniel stops to tie his shoelace and, while at rest, is struck by Rebecca, who is moving at 14.0 m/s before she collides with him. After the collision, Rebecca has a velocity of magnitude 8.00 m/s at an angle of 53.1 ∘ from her initial direction. Both skaters move on the frictionless, horizontal surface of the rink. Part A What is the magnitude of...

((8.27)Q:7) Two ice skaters, Daniel (mass 70.0 kg ) and Rebecca (mass 45.0 kg ), are...

((8.27)Q:7) Two ice skaters, Daniel (mass 70.0 kg ) and Rebecca (mass 45.0 kg ), are practicing. Daniel stops to tie his shoelace and, while at rest, is struck by Rebecca, who is moving at 14.0 m/s before she collides with him. After the collision, Rebecca has a velocity of magnitude 8.00 m/s at an angle of 55.1 ∘ from her initial direction. Both skaters move on the frictionless, horizontal surface of the rink. A) What is the magnitude of...

John’s mass is 98.6 kg, and Barbara’s is 67.0 kg. He is standing on the x...

John’s mass is 98.6 kg, and Barbara’s is 67.0 kg. He is standing on the x axis at xJ = +9.45 m, while she is standing on the x axis at xB = +4.39 m. They switch positions. How far and in which direction does their center of mass move as a result of the switch?

What is the classical and relativistic momentum of an object with a mass of 5 kg...

What is the classical and relativistic momentum of an object with a mass of 5 kg moving at a speed of 0.8c?

Data Table A Mass of Cart (kg) Impulse (N.s) Velocity (m/s) Momentum (N.s) Change in Momentum...

Data Table A Mass of Cart (kg) Impulse (N.s) Velocity (m/s) Momentum (N.s) Change in Momentum % Diff. Before After Before After 0.2695 +0.351 - 0.673 +0.659 Data Table B Mass of Cart + mass bar (kg) Impulse (N.s) Velocity (m/s) Momentum (N.s) Change in Momentum % Diff. Before After Before After 0.4695 +0.346 -0.377 +0.372 % Difference= 2×(Change in momentum-Impulse)(Change in momentum+Impulse)×100= Questions What are possible reasons why the change in momentum is different from the measured impulse?...

Question