The value is almost always less than one due to initial translational kinetic energy being lost to rotational kinetic energy, plastic deformation, and heat .
What does it mean when the coefficient of restitution is less than 1?
Values of the coefficient of restitution
If it’s on the higher side (i.e., close to 1), it suggests that very little kinetic energy is lost during the collision; on the other hand, if the value is low, it indicates that a large amount of kinetic energy is converted into heat or otherwise absorbed through deformation .
Can the coefficient of restitution be less than 1?
It normally ranges from 0 to 1 where 1 would be a perfectly elastic collision. ... It can be more than 1 if there is an energy gain during the collision from a chemical reaction, a reduction in rotational energy, or another internal energy decrease that contributes to the post-collision velocity.
What happens when coefficient of restitution 1?
This formula is Newton’s law of restitution. The coefficient of restitution always satisfies 0≤e≤1. When e=0, the balls remain in contact after the collision. When e= 1, the collision is elastic: there is no loss of kinetic energy .
Can the coefficient of friction be greater than 1?
A coefficient of friction that is more than one just means that friction is stronger than the normal force . An object such as silicon rubber for example, can have a coefficient of friction much greater than one. This can be explained as below: ... Hence, the coefficient of friction becomes greater than one.
What is the SI unit of coefficient of restitution?
coefficient of restitution has no unit , it is a dimensionless ratio. Explanation: Coefficient of restitution (COR) is the ratio of the relative velocity of an object after collision to the relative velocity of the object before collision. COR generally lies between 0 to 1 for most of the conditions.
What is the maximum coefficient of restitution?
The coefficient of restitution provides us with information about the elasticity of the collision. Collisions in which there is no loss of overall kinetic energy is known as a perfectly elastic collision. This type of collision has the maximum coefficient of restitution of e = 1 .
Can coefficient of restitution be negative?
This paper shows that negative coefficients of normal restitution occur inevitably when the interaction force between colliding particles is finite . We derive an explicit criterion showing that for any set of material properties there is always a collision geometry leading to negative restitution coefficients.
How do you calculate coefficient of restitution?
Analysis. Coefficient of Restitution = speed up/speed down . Where v = velocity, g = 9.8m/s 2 , and h = average height measured. We took the average of the bounced height value (h) and put it in the formula along with the initial height (H) of 92 cm.
Does coefficient of restitution depend on height?
Johnson said, “Each time the bounce height reduces by roughly the same factor, the coefficient of restitution.” On the other hand, a physics student Paul Ryan experimentally showed that the coefficient of restitution does depend on the height ; and his graphs look similar to mine (also with large variance in the data).
What is the dimensional formula of coefficient of restitution?
Answer: b) ML-1T-2 is the dimensional formula for coefficient of restitution.
Is coefficient of restitution always positive?
A collision where the maximum kinetic (movement) energy is lost is called a perfectly inelastic collision, and this is where the two objects stick together and move together after the collision. They have a coefficient of restitution of e = 0. ... The coefficient of restitution is always positive .
Does coefficient of restitution depend on initial velocity?
The coefficient of restitution depends on many elements, such as the geometry of the bodies in contact, the approach velocity, the material properties, the duration of contact and, possibly, friction [13]. In Newton’s model the coefficient of restitution is defined as the ratio of final to initial velocity .
What is the highest coefficient of friction?
The highest coefficients of static friction are for dry contact between identical metals . Baluncore said: The highest coefficients of static friction are for dry contact between identical metals.
What is the max coefficient of static friction?
Eventually maximum static friction force is exceeded and the book moves. The maximum static friction force is: (f s ) max = μ s N where μ s is the coefficient of static friction. Static friction is subtle because the static friction force is variable and depends on the external forces acting on an object.
Is it always necessary that the friction coefficient is less than 1?
It is not necessary that the friction coefficient is always less than 1. When the friction is stronger than the normal reaction force, the coefficient of friction is greater than 1. For example, silicon rubber has the coefficient of friction greater than 1.
