A body of mass 25kg, moving at 3m/s on a rough horizontal floor is brought to after sliding through a distance of 2.5m on the floor. Calculate the coefficient of sliding friction.
1.84
v²=u²+2as
3²=2as
9=2×a×2.5
a=9/5
a=1.8ms-²
F=ma
F=25×1.8=45N
F=mg=25×10=250
Coefficient of friction = limiting force/normal reaction
Coefficient =45/250
=0.18
Correct
To calculate the coefficient of sliding friction, we need to consider the forces acting on the body. In this case, there are mainly two forces:
1. The force due to the sliding friction, which opposes the motion of the body.
2. The force due to the mass of the body, which can be calculated using Newton's second law (F = ma).
First, let's calculate the force due to the mass of the body:
F = ma = (25 kg)(3 m/s^2) = 75 N
From here, we need to find the force of sliding friction. To do this, we can use the equation:
Ffriction = u * Fn
Where:
Ffriction is the force of sliding friction,
u is the coefficient of sliding friction,
Fn is the normal force.
In this case, the normal force is equal to the weight of the body, since it is on a horizontal floor:
Fn = mg = (25 kg)(9.8 m/s^2) = 245 N
Now we can solve for the coefficient of sliding friction:
Ffriction = (coefficient of sliding friction) * Fn
75 N = u * 245 N
Solving for u:
u = 75 N / 245 N
u ≈ 0.31
Therefore, the coefficient of sliding friction in this case is approximately 0.31.