One of the most powerful laws in physics is the law of momentum conservation. The law of momentum conservation can be stated as follows. For a collision occurring between object 1 and object 2 in an isolated system, the total momentum of the two objects before the collision is equal to the total momentum of the two objects…
The Law of Action-Reaction A collision is an interaction between two objects that have made contact (usually) with each other. As in any interaction, a collision results in a force being applied to the two colliding objects. Newton’s laws of motion govern such collisions. In the second unit of The Physics Classroom, Newton’s third law of…
Occasionally when objects collide, they bounce off each other as opposed to sticking to each other and traveling with the same speed after the collision. Bouncing off each other is known as rebounding. Rebounding involves a change in the direction of an object; the before- and after-collision direction is different. Rebounding was pictured and discussed earlier in Lesson 1. At that…
First we will examine the importance of the collision time in affecting the amount of force that an object experiences during a collision. In a previous part of Lesson 1, it was mentioned that force and time are inversely proportional. An object with 100 units of momentum must experience 100 units of impulse in order to…
In a collision, an object experiences a force for a given amount of time that results in its massundergoing a change in velocity (i.e., that results in a momentum change). There are four physical quantities mentioned in the above statement – force, time, mass, and velocity change. The force multiplied by the time is known as the impulse and the mass multiplied by…
From the definition of momentum, it becomes obvious that an object has a large momentum if both its mass and its velocity are large. Both variables are of equal importance in determining the momentum of an object. Consider a Mack truck and a roller skate moving down the street at the same speed. The considerably…
Momentum is a vector quantity. As discussed in an earlier unit, a vector quantity is a quantity that is fully described by both magnitude and direction. To fully describe the momentum of a 5-kg bowling ball moving westward at 2 m/s, you must include information about both the magnitude and the direction of the bowling ball. It is not enough…
Momentum The sports announcer says, “Going into the all-star break, the Chicago White Sox have themomentum.” The headlines declare “Chicago Bulls Gaining Momentum.” The coach pumps up his team at half-time, saying “You have the momentum; the critical need is that you use thatmomentum and bury them in this third quarter.” Momentum is a commonly used term in sports. A team that has the momentum…
Double Trouble in 2 Dimensions In the Newton’s laws unit, the topic of two-body problems was introduced. A pair of problem-solving strategies were discussed and applied to solve three example problems. Such two-body problems typically involve solving for the acceleration of the objects and the force that is acting between the objects. One strategy for solving two-body…
When all the forces that act upon an object are balanced, then the object is said to be in a state of equilibrium. The forces are considered to be balanced if the rightward forces are balanced by the leftward forces and the upward forces are balanced by the downward forces. This however does not necessarily mean that all…