Advertisements
Advertisements
प्रश्न
A spherical ball is dropped in a long column of a viscous liquid. The speed of the ball as a function of time may be best represented by the graph
विकल्प
A
B
C
D
Advertisements
उत्तर
Initially, when the ball starts moving, its velocity is small. Gradually, the velocity of the ball increases due to acceleration caused by gravity. However, as the velocity increases, the viscous force acting on the ball also increases. This force tends to decelerate the ball. Therefore, after reaching a certain maximum velocity, the ball slows down.
APPEARS IN
संबंधित प्रश्न
The force of viscosity is
The viscous force acting between two layers of a liquid is given by \[\frac{F}{A} = - \eta\frac{dv}{dz}\]. This F/A may be called
A raindrop falls near the surface of the earth with almost uniform velocity because
Estimate the speed of vertically falling raindrops from the following data. Radius of the drops = 0.02 cm, viscosity of air = 1.8 × 10−4 poise, g= 9.9 × 10 ms−2 and density of water = 1000 kg m−3.
The unit of viscosity is
With an increase in temperature, the viscosity of liquid and gas, respectively will __________.
Define the coefficient of viscosity of a liquid.
A small metal sphere of mass M and density d1, when dropped in a jar filled with liquid moves with terminal velocity after sometime. The viscous force acting on the sphere is (d2 = density of liquid and g = gravitational acceleration)
From amongst the following curves, which one shows the variation of the velocity v with time t for a small-sized spherical body falling vertically in a long column of a viscous liquid.
Analogy
Viscous force: ______:: Buoyant force: ______.
Clouds float in the air due to ______.
The velocity of a small ball of mass M and density d, when dropped in a container filled with glycerine becomes constant after some time. If the density of glycerine is `"d"/2` , then the viscous force acting on the ball will be ______.
Is viscosity a vector?
A solid ball of density ρ1 and radius r falls vertically through a liquid of density ρ2. Assume that the viscous force acting on the ball is F = krv, where k is a constant and v its velocity. What is the terminal velocity of the ball?
A liquid of density ρ and coefficient of viscosity η flows with velocity v through a tube of diameter D. A quantity `"R" = (rho"vD")/η`, determines whether the flow will be streamlined or turbulent. R has the dimension of ______.
State the formula and S.I. units of coefficient of viscosity.
Define velocity gradient.
The dimensions of coefficient of viscosity are ______.
