Answer:
Surface tension is the tendency of liquid surfaces to shrink into the minimum surface area possible.
Surface tension is caused by effects of intermolecular forces at liquid interface.
Surface tension increases as intermolecular forces increases.
Explanation:
- Surface tension is the tendency of liquid surfaces to shrink into the minimum surface area possible. It can also be seen as the energy required to increase the surface of a liquid by a unit amount.
- Surface tension is caused by the mediating effects of intermolecular forces at the liquid interfaces. Example in water, surface tension is caused by the mediating effect of the force between hydrogen and oxygen molecules. Liquids tends to reduce their surface area because of inward attarction of the liquid molecules.
- Surface tension increases as intermolecular forces increases. Also, surface tension decreases as intermolecular forces decreases.
Answer: To focus on a near object – the lens becomes thicker, this allows the light rays to refract (bend) more strongly. To focus on a distant object – the lens is pulled thin, this allows the light rays to refract slightly.
Explanation:
Answer:
Explanation:
The centripetal force acting on the car must be equal to mv²/R, where m is the mass of the car, v its speed and R the radius of the curve. Since the only force acting on the car that is in the direction of the center of the circle is the frictional force, we have by the Newton's Second Law:
But we know that:
And the normal force is given by the sum of the forces in the vertical direction:
Finally, we have:
So, the minimum value for the coefficient of friction is 0.27.
