Advertisements
Advertisements
प्रश्न
A long stick rests on the surface. A person standing 10 m away from the stick. With what minimum speed an object of mass 0.5 kg should he has thrown so that it hits the stick. (Assume the coefficient of kinetic friction is 0.7).
Advertisements
उत्तर
Given,
Distance (s) = 10 m
Mass of the object (m) = 0.5 kg
Coefficient of kinetic friction (µ) = 0.7
Work done in moving a body in horizontal surface ω
= µR × s = µmg × s
This work done is equal to initial kinetic energy of the object
`1/2mv^2` = µ mg s
∣`v^2`∣ = 2 µgs = 2 × 0.7 × 9.8 × 10
v2 = 14 × 9.8 = 137. 2
v = 11. 71 ms-1
APPEARS IN
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 ______
Explain various types of friction.
Suggest a few methods to reduce friction.
State the empirical laws of static and kinetic friction.
People often say “For every action, there is an equivalent opposite reaction”. Here they meant ‘action of a human’. Is it correct to apply Newton’s third law to human actions? What is mean by ‘action’ in Newton's third law? Give your arguments based on Newton’s laws.
A uniform metal chain is placed on a rough table such that one end of the chain hangs down over the edge of the table. When two-thirds of its chain length hangs over the edge the chain start sliding. Then the coefficient of static friction is:
A block of mass 20 kg is sliding on a surface is inclined at an angle of 45° with the horizontal. What will be the acceleration of the block if the coefficient of kinetic friction between the block and the surface is 0.7?
A chain of mass 'M' and length 'L' is put on a rough horizontal surface and is pulled by constant horizontal force 'F' as shown in the figure. The velocity of the chain as it turns completely ______.
(Coefficient of friction = μ)
The coefficient of static friction between a car's tires and a level road is 0.80. If the car is to be stopped in a maximum time of 3.0 s, its speed cannot exceed.
A body starts from rest on a long inclined plane of slope 45°. The coefficient of friction between the body and the plane varies as µ = 0.3 x, where x is distance travelled down the plane. The body will have maximum speed (for g = 10 m/s2) when x = ______.
