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प्रश्न
Explain various types of friction.
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उत्तर
There are two types of Friction:
(1) Static Friction:
Static friction is the force that opposes the initiation of motion of an object on the surface. The magnitude of static frictional force fs lies between
0 ≤ fs ≤ μsN
where, µs – coefficient of static friction
N – Normal force
(2) Kinetic friction:
The frictional force exerted by the surface when an object slides is called kinetic friction. Also called sliding friction or dynamic friction,
fk – µkN
where µk – the coefficient of kinetic friction
N – Normal force exerted by the surface on the object
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संबंधित प्रश्न
An object of mass m begins to move on the plane inclined at an angle θ. The coefficient of static friction of inclined surfaces is µs. The maximum static friction experienced by the mass is ______
State the empirical laws of static and kinetic friction.
Two masses m1 and m2 are connected with a string passing over a frictionless pulley fixed at the comer of the table as shown in the figure. The coefficient of static friction of mass m1 with the table is µs Calculate the minimum mass m3 that may be placed on m1 to prevent it from sliding. Check if m1 = 15 kg, m2 = 10 kg, m3 = 25 and µs = 0.2.
A block of mass m slides along a floor while a force of magnitude F is applied to it at an angle θ as shown in figure. The coefficient of kinetic friction is µK. Then, the block's acceleration 'a' is given by ______.
(g is acceleration due to gravity)
A 40 kg wooden crate is being pushed across a wooden floor with a force of 160 N. If µk = 0.3, the acceleration of the crate is ______ m/s2. (g = 10 m/s2}
A block of mass m = 1 kg moving on horizontal surface with speed u = 2 m/s enters a rough horizontal patch ranging from x = 0.10 m to x = 2.00 m. If the retarding force fr on the block in this range is inversely proportional to x over this range i.e.
fr = `"-k"/x` 0.10 < x < 2.00
= 0 for x < 0.10 and x > 2.00
If k = 0.5 J then the speed of this block as it crosses the patch is (use ℓn 20 = 3)
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Starting from rest, a body slides down a 45° inclined plane in twice the time it takes to slide down the same distance in the absence of friction. The coefficient of friction between the body and the inclined plane is ______.
There are two inclined surfaces of equal length (L) and same angle of inclination 45° with the horizontal. One of them is rough and the other is perfectly smooth. A given body takes 2 times as much time to slide down, on rough surface than on the smooth surface. The coefficient of kinetic friction (μ) between the object and the rough surface is close to ______.
