Q1. Frictional force is a contact force. Support the statement by giving two examples from
your daily life.
Q2 Identify the type of forces acting in the following cases:
i) Blood being pushed by our arteries.
ii) Horse pulling a cart
iii) A child lifting a school bag
iv) Kicking a foot ball
v) During dry weather, clothes made of synthetic fibre often stick to the skin.
vi) While sieving grains, small pieces fall down.
vii) Two thermocol balls held close to each other move away when released.
viii) Force responsible for the downward motion of a man with a parachute.
ix) Deflection in the compass needle when placed near current carrying conductor.
Q3 .Distinguish between muscular force and ggravitational force.
Q4 . Write one point of similarity and one point of difference between:
Gravitational force and magnetic force.
Q5. State the force that acts on all bodies on the earth at all times.
Q6 . Name a force that always opposes motion of an object.
Q 7.If you use a stick to push an object, the muscular force acting on the object is a non
contact force since your body is not in contact with the object. True or False? Explain.
Answers
Answer:
Friction is a contact force when two surfaces interact. The second equation is the kinetic frictional force that is used when two surfaces are sliding against each other.
Moving a couch across a floor, pushing a car up a hill, kicking a ball or pushing a desk across a room are some of the everyday examples where contact forces are at work. In the first case the force is continuously applied by the person on the car, while in the second case the force is delivered in a short impulse.
Hope this helps you.
Explanation:
Q3GRAVITATIONAL FORCE IS A NON CONTACT FORCE WHILE MUSCULAR FORCE IS A CONTACT FORCE. MUSCULAR STRENGTH CAN BE SEEN THROUGH OUR EYES BUT GRAVITATIONAL FORCE CANNOT BE SEEN THROUGH OUR EYES.
Q4
These are very similar equations. The fundamental reason for this relates to continuity laws, since we can imagine integrating across the whole surface and finding a constant only proportional to the enclosed volume (Gauss's law), but I will assume that is above your paygrade
Difference: Masses aren't negative
The major difference between these two is that gravity is never repulsive. If you put two like charges together, you will always get repulsion. On the other hand, all masses are seemingly attractive, i.e. there is no negative mass like there exists negative charg e
Q5Gravitational force is the force which acts all the time on all the bodies present on the earth. It's equal to the weight of a body and always directed towards the center of the earth.
Q6Friction is the opposing force reacting to the motion of an object. It is the force between two objects that can result in different energies. Friction is very important as when it does not exist when you are driving your car or a bike, it will seem you are riding it on an ice and you cannot stop.
Q7False.
Contact forces are those forces in which direct contact between the two bodies is required. The contact may also be with the help of a stick or a piece of rope.
If we use a stick to push an object, we have made the contact with the help of stick. This push or force is caused by the action of muscles in our body. This muscular force is a contact force