Basically velocity is a vector quantity and is specified in m/s (meters/second). Speed is the distance traveled by an object where as, velocity is distance traveled by an object per unit time in a particular direction. Speed is a scalar quantity where as velocity is a vector quantity
To solve this problem we will use the concepts related to thermal expansion in a body for which the initial length, the coefficient of thermal expansion and the temperature change are related:

Where,
= Change in Length
= Coefficient of linear expansion
= Change in temperature
= Initial Length
Our values are:


Replacing we have,



Therefore the change in milimiters was 0.4126mm
It depends on the type of question, mechanical condition and given values,
You can use the formula,
Coefficient of kinetic friction = Force of Kinetic friction / Normal force (perpendicular to contacting surfaces)
Hope this helps!
Work is done when a spring is extended or compressed . Elastic potential energy is stored in the spring hope that helpss.