How to calculate magnitude of frictional force?
The correct answer and explanation is:
The magnitude of the frictional force can be calculated using the formula: Ff=μ⋅FNF_f = \mu \cdot F_N
Where:
- FfF_f is the frictional force
- μ\mu is the coefficient of friction (which can be static or kinetic, depending on the type of friction)
- FNF_N is the normal force, which is the force exerted by a surface perpendicular to the object in contact.
Explanation:
Friction is the force that resists the relative motion or tendency of such motion between two surfaces in contact. The magnitude of the frictional force depends on two main factors: the nature of the surfaces in contact and the force pressing them together.
- Coefficient of Friction (μ\mu): The coefficient of friction is a dimensionless quantity that characterizes the frictional properties between two surfaces. There are two types of coefficients: static friction (when the object is not moving) and kinetic friction (when the object is sliding). Static friction is usually higher than kinetic friction, meaning it takes more force to initiate motion than to maintain it.
- Normal Force (FNF_N): The normal force is the force exerted by a surface that is perpendicular to the object. For a horizontal surface with no incline, the normal force is simply the weight of the object, which is given by:
FN=m⋅gF_N = m \cdot g
Where:
- mm is the mass of the object
- gg is the acceleration due to gravity (approximately 9.8 m/s29.8 \, \text{m/s}^2).
- Calculating Frictional Force: The frictional force FfF_f is directly proportional to the normal force. The stronger the force pressing the object into the surface, the greater the frictional force. For example, increasing the weight of an object will increase the frictional force between it and the surface it is resting on.
In conclusion, the magnitude of the frictional force can be calculated by multiplying the coefficient of friction by the normal force.