An ice hockey forward with mass 71.0 kgkg is skating due north with a speed of 5.50 m/sm/s. As the forward approaches the net for a slap shot, a defensive player (mass 110 kgkg) skates toward him in order to apply a body-check. The defensive player is traveling south at 4.40 m/sm/s just before they collide.Part AIf the two players become intertwined and move together after they collide, in what direction and at what speed do they move after the collision? Friction between the two players and the ice can be neglected.Express your answer with the appropriate units. Enter positive value if the velocity is northward and negative value if the velocity is southward.Activate to select the appropriates template from the following choices. Operate up and down arrow for selection and press enter to choose the input value typeActivate to select the appropriates symbol from the following choices. Operate up and down arrow for selection and press enter to choose the input value typev𝑣 =nothing
Question
An ice hockey forward with mass 71.0 kgkg is skating due north with a speed of 5.50 m/sm/s. As the forward approaches the net for a slap shot, a defensive player (mass 110 kgkg) skates toward him in order to apply a body-check. The defensive player is traveling south at 4.40 m/sm/s just before they collide.Part AIf the two players become intertwined and move together after they collide, in what direction and at what speed do they move after the collision? Friction between the two players and the ice can be neglected.Express your answer with the appropriate units. Enter positive value if the velocity is northward and negative value if the velocity is southward.Activate to select the appropriates template from the following choices. Operate up and down arrow for selection and press enter to choose the input value typeActivate to select the appropriates symbol from the following choices. Operate up and down arrow for selection and press enter to choose the input value typev𝑣 =nothing
Solution
This problem can be solved using the principle of conservation of momentum. The total momentum before the collision is equal to the total momentum after the collision.
The momentum of an object is given by the product of its mass and velocity.
Before the collision:
- The momentum of the forward player is (71.0 kg * 5.50 m/s) = 390.5 kg*m/s (northward)
- The momentum of the defensive player is (110 kg * 4.40 m/s) = 484 kg*m/s (southward)
The total momentum before the collision is the difference between the two momenta, taking into account their directions. So, the total momentum before the collision is (390.5 kgm/s - 484 kgm/s) = -93.5 kg*m/s. The negative sign indicates that the total momentum is southward.
After the collision, the two players move together. So, their total mass is (71.0 kg + 110 kg) = 181 kg.
The velocity of the two players after the collision (v) can be found by dividing the total momentum by the total mass: v = total momentum / total mass = -93.5 kg*m/s / 181 kg = -0.516 m/s.
The negative sign indicates that the velocity is southward. So, after the collision, the two players move together in the southward direction at a speed of 0.516 m/s.
Similar Questions
A 15.0-gram air hockey puck sliding on a horizontal surface at a velocity of 7.00 meters per second northcollides with a 15.0-gram air hockey puck traveling at a velocity of 8.00 meters per second south. Themomentum of the system of pucks after the collision is
A 90-kg halfback running north with a speed of 10 m/s is tackled by a 120-kg opponent running south at 5.0 m/s. The collision is perfectly inelastic. Compute the velocity of the two players just after the tackle.Select one:a.1.4 m/s southb.2.8 m/s southc.1.4 m/s northd.2.8 m/s north
Two skaters, each of mass 35 kg, approach each other along parallel paths separated by 3.6 m. They have equal and opposite velocities of 1.4 m/s. The first skater carries one end of a long pole with negligible mass, and the second skater grabs the other end of it as she passes. See Fig. 12-42. Assume frictionless ice.Figure 12-42(a) Describe quantitatively the motion of the skaters after they have become connected by the pole.1.8 1.8 m (radius)0.78 0.778 rad/s (angular speed)(b) By pulling on the pole, the skaters reduce their separation to 1.0 m. What is their angular speed then?10.08 10.1 rad/s(c) Calculate the kinetic energy of the system in (a) and (b).69.3 68.6 J (energy for system a)889.056 889 J (energy for system b)(d) What is the source of the added kinetic energy?
A hockey puck with a mass of 160 g slides at a speed of 12 m/s on frictionless ice. The puck runs into a small box with a mass of 850 g that is initially at rest. Assuming that the collision is elastic, what is the speed of the hockey puck after the collision?
A 52 kg ice hockey player moving at 11 m/s slows down and stops over a displacement of8.0 m. T/I C(a) Calculate the net force on the skater.
Upgrade your grade with Knowee
Get personalized homework help. Review tough concepts in more detail, or go deeper into your topic by exploring other relevant questions.