Momentum and collision calculator (elastic and inelastic)
Momentum and collision calculator: final velocities, total momentum and kinetic energy lost in an elastic, inelastic or partly elastic head-on collision.
Momentum and collision calculator (elastic and inelastic) గురించి
In a collision between two bodies, the total momentum m₁u₁ + m₂u₂ is the same before and after. The coefficient of restitution e, the ratio of separation speed to approach speed, supplies the second equation: e = 1 is a perfectly elastic collision and e = 0 means the bodies stick together. The two equations give both final velocities, and comparing ½mv² before and after gives the kinetic energy lost.
The default, a 2 kg body at 3 m/s meeting a 1 kg body moving at −1 m/s elastically, sends them off at 0.333 m/s and 4.333 m/s. A 1,000 kg car at 20 m/s that locks onto a parked 1,500 kg car moves off at 8 m/s, and 60% of the kinetic energy goes into deformation, heat and sound.
Motion is along one line: choose a positive direction and give velocities the other way a minus sign. External forces such as road friction are taken as negligible during the impact.
పరిష్కరించిన ఉదాహరణలు
Equal masses, elastic: velocities swap
Collision
Elastic
Mass of body 1
1 kg
Velocity of body 1 before
2 m/s
Mass of body 2
1 kg
Velocity of body 2 before
0 m/s
Show velocities in
m/s
Velocity of body 1 after
0 m/s
Velocity of body 2 after
2 m/s
Kinetic energy lost
0 J
తనిఖీ చేసిన మూలం: OpenStax UP1 §9.4: equal-mass elastic collision exchanges velocities
Car hits a parked car and they lock
Collision
Perfectly inelastic
Mass of body 1
1000 kg
Velocity of body 1 before
20 m/s
Mass of body 2
1500 kg
Velocity of body 2 before
0 m/s
Show velocities in
m/s
Velocity of body 1 after
8 m/s
Velocity of body 2 after
8 m/s
Kinetic energy before
200,000 J
Kinetic energy after
80,000 J
Share of kinetic energy lost
60.00%
తనిఖీ చేసిన మూలం: Python 3.8 decimal: v = 20000/2500 = 8; KE 200000 → 80000 J
e = 0.5 head-on
Collision
Coefficient e
Coefficient of restitution e
0.5
Mass of body 1
2 kg
Velocity of body 1 before
3 m/s
Mass of body 2
1 kg
Velocity of body 2 before
-1 m/s
Show velocities in
m/s
Velocity of body 1 after
1 m/s
Velocity of body 2 after
3 m/s
Total momentum (conserved)
5 kg·m/s
Kinetic energy lost
4 J
తనిఖీ చేసిన మూలం: Python 3.8 fractions: v1 = (5 + 1·0.5·(−4))/3 = 1, v2 = (5 + 2·0.5·4)/3 = 3; KE 9.5 → 5.5 J
Heavy ball hits a light one, elastic
Collision
Elastic
Mass of body 1
10 kg
Velocity of body 1 before
1 m/s
Mass of body 2
1 kg
Velocity of body 2 before
0 m/s
Show velocities in
m/s
Velocity of body 1 after
0.818182 m/s
Velocity of body 2 after
1.81818 m/s
తనిఖీ చేసిన మూలం: Python 3.8 fractions: v1 = 9/11, v2 = 20/11
ప్రశ్నలు
What is the difference between elastic and inelastic collisions?
Both conserve momentum; only an elastic collision also conserves kinetic energy. In a perfectly inelastic collision the bodies stick together and lose the most kinetic energy that momentum conservation allows. When a 1,000 kg car at 20 m/s locks onto a parked 1,500 kg car, momentum stays at 20,000 kg·m/s while kinetic energy falls from 200 kJ to 80 kJ. Most real collisions fall between the two extremes.
What is the coefficient of restitution?
It is the relative speed after a collision divided by the relative speed before, e = (v₂ − v₁) ÷ (u₁ − u₂), a number from 0 to 1. For a ball dropped onto a rigid floor, e = √(bounce height ÷ drop height). The ITF requires a type 2 tennis ball dropped from 254 cm onto concrete to rebound 135–147 cm, which corresponds to e between 0.73 and 0.76.
How do you calculate momentum?
Momentum is mass times velocity, p = mv, measured in kg·m/s. It has a direction, so velocities in opposite directions carry opposite signs. A 1,000 kg car at 20 m/s has 20,000 kg·m/s. With no outside forces the total is the same before and after a collision, which is why two 2 kg carts meeting head-on at 5 m/s and sticking together stop dead.
What happens when two equal masses collide elastically?
They swap velocities. A 1 kg ball at 2 m/s hitting an identical ball at rest stops, and the second ball leaves at 2 m/s with all the kinetic energy; a Newton's cradle shows the same effect. With unequal masses the lighter body leaves faster: a 10 kg ball at 1 m/s sends a 1 kg ball off at 1.82 m/s and slows to 0.82 m/s.
“Momentum and collision calculator (elastic and inelastic)” ఎంత కచ్చితమైనది?
కచ్చితత్వం మీ ఇన్పుట్లు, పద్ధతిలోని ఊహలపై ఆధారపడి ఉంటుంది. దశాంశ గణన 50 సార్థక అంకెలను ఉపయోగిస్తుంది. అంచనాలు, సంఖ్యా పద్ధతులు, మూల డేటా తక్కువ కచ్చితత్వంతో ఉండవచ్చు; ప్రదర్శనలో విలువలను రౌండ్ చేయడం ఈ పరిమితులను తొలగించదు. స్వతంత్ర మూలాల పరిష్కారాలతో తనిఖీ చేసిన ఉదాహరణలు: 5. ఉదాహరణకు, “Equal masses, elastic: velocities swap”ను OpenStax UP1 §9.4: equal-mass elastic collision exchanges velocitiesతో తనిఖీ చేశారు.
ఈ పద్ధతికి మూలం ఏమిటి?
OpenStax University Physics Volume 1, §9.4 Types of collisions; HyperPhysics — Elastic and inelastic collisions; coefficient of restitution.
ఈ కాలిక్యులేటర్లో స్వతంత్ర ఆధారాల నుంచి సమాధానాలు పొందిన 5 సాధించిన ఉదాహరణలు ఉన్నాయి. ఇవి పరీక్షల సమూహంలో అమలవుతాయి; మీరు ఇక్కడ కూడా వాటిని అమలు చేయవచ్చు.