Answer the following questions:
1. Explain how the convection currents arise as a result of variations in density of liquids and gases with temperature.
2. State some of the practical applications of relative density.
3. Explain the variation of density in solids, liquids and gases due to the change in temperature.
4. Can a body have constant speed as well as variable velocity? Is yes, give one example.
5. Speed and velocity have the same unit yet they are different physical identities. Why? 6. What are the factors that affect the time period of a pendulum?
7. A car moving on a crowded road is an example of non-uniform motion. Explain.
all are hard questions, try. best will marked as brainliest
Answers
Explain how the convection currents arise as a result of variations in density of liquids and gases with temperature.
The convection currents tend to move a fluid or gas particles from one place to another. These are created as a result of the differences occurring within the densities and temperature of a specific gas or a fluid. Due to this temperature difference, the hot fluids tend to rise, whereas cold fluids tend to sink.
State some of the practical applications of relative density.
1)
It is used for determining the density of unknown substance from the known density of another substance.
2)
It is used by geologist to find out the mineral content into the rock.
3)
Testing purity of a substance (example gold).
Explain the variation of density in solids, liquids and gases due to the change in temperature.
The density of a material varies with temperature and pressure. This variation is typically small for solids and liquids but much greater for gases. Increasing the pressure on an object decreases the volume of the object and thus increases its density. This causes it to rise relative to more dense unheated material.
Can a body have constant speed as well as variable velocity? Is yes, give one example.
Yes, a body has constant speed as well as variable velocity.
A particle moving in a circular path with a uniform circular motion.
Now as we know that in a circular motion the direction of the particle is always changing at every instànt of time (checkout the diagram above) it is not uniform so the velocity of the particle is also changed as the velocity is a vector quantity (magnitude as well as direction), but speed is a scalar quantity (magnitude only).
The body has velocity v1,v2,v3, and v4 at different interval of times as shown in the figure, but the speed of the body is uniform.
So we can say that a body has constant speed as well as variable velocity.
So this is the required answer.
Speed and velocity have the same unit yet they are different physical identities. Why?
Speed and velocity have the same unit yet they are different physical identities because speed is a scalar quantity whereas velocity is a vector quantity. Speed has no direction, only magnitude whereas velocity has both magnitude as well as direction. That's why there can be a difference in their values.
What are the factors that affect the time period of a pendulum?
The only things that affect the period of a simple pendulum are its length and the acceleration due to gravity. The period is completely independent of other factors, such as mass.
A car moving on a crowded road is an example of non-uniform motion. Explain.
A car driven on any city road is an example of non-uniform motion because city roads are usually full of traffic and you have to apply brakes,change the speed and even wait for the traffic signals so as the definition says when a body does not covers equal distance in equal interval of time it is known as non-uniform motion.
