Respuesta :
Answer:
μ = 0.18
Explanation:
Let's use Newton's second Law, the coordinate system is horizontal and vertical
Before starting to move the box
Y axis
N-W = 0
N = W = mg
X axis
F -fr = 0
F = fr
The friction force has the formula
fr = μ N
fr = μ m g
At the limit point just before starting the movement
F = μ m g
μ = F / m g
calculate
μ = 34.8 / (19.8 9.8)
μ = 0.18
Answer:
The coefficient of friction between the crate and the floor = 0.143
Explanation:
Frictional Force: This is the force that act between two surface in contact and tend to oppose their motion. it is measured in Newton (N)
F - F₁ = ma.................... Equation 1
Where F = Force of the crate, F₁ = frictional force, m = mass of the crate, a = acceleration of the crate
making F₁ the subject the equation 1
F₁ = F - ma .................... Equation 2
Given: F = 34. 8 N, m = 19.8 kg. a = 0.357 m/s².
Substituting these values into equation 2
F₁ = 34.8 - (19.8×0.357)
F₁ = 34.8 - 7.07
F₁ = 27.73 N.
F₁ = μR ............... equation 3
making μ the subject of formula in equation 3
μ = F₁/R.............. Equation 4
Where F₁ = Frictional Force, μ = coefficient of static friction, R = Normal reaction.
R = mg,
where g = 9.8 m/s², m = 19.8 kg
R = 19.8( 9.8) = 194.04 N,
R = 194.04 N, F₁ = 27.73 N
Substituting these values into equation 4
μ = 27.73/194.04
μ = 0.143.
therefore the coefficient of friction between the crate and the floor = 0.143
