GROUP B
21. What is contact force and non-contact force? Give examples
What is Gravitational force?
22. What is the relation between force and pressure? Force has magnitude as well as direction. (
state true or false) Explain why sportsmen use shoes with spikes?
23. Suppose your writing desk is tilted a little. A book kept on it starts sliding down. Show
direction of frictional force acting on it. Why friction arise between two surfaces in contact?
24. What are weeds? How can we control them?
25. Why the saucepan handles are made of thermosetting plastic? Explain it.
OR
Write down two uses of nylon and rayon.
26. What are the advantages of manure?
27. If wheat is sown in the month of June, what would happen? Discuss
OR
How will you select the seeds for sowing?
28.State the differences between eukaryotes and prokaryotes.
29.Cells are the basic structural units of living organisms. Explain.
OR
What are communicable diseases ? Name three diseases caused by virus
30. What are antibiotics? Name three antibiotics made from bacteria and fungi.
no
bahi please bata dho answer
Answers
→ Contact force : contact force is any force that requires contact to occur. Contact forces are ubiquitous and are responsible for most visible interactions between macroscopic collections of matter. Pushing a car up a hill or kicking a ball across a room are some of the everyday examples where contact forces are at work.
ex→
Reaction force. An object at rest on a surface experiences reaction force . ...
Reaction force. An object at rest on a surface experiences reaction force . ...Tension. An object that is being stretched experiences a tension force. ...
Reaction force. An object at rest on a surface experiences reaction force . ...Tension. An object that is being stretched experiences a tension force. ...Friction. Two objects sliding past each other experience friction forces. ...
Reaction force. An object at rest on a surface experiences reaction force . ...Tension. An object that is being stretched experiences a tension force. ...Friction. Two objects sliding past each other experience friction forces. ...Air resistance.
→ Non contact force
A non-contact force is a force which acts on an object without coming physically in contact with it. The most familiar non-contact force is gravity, which confers weight. In contrast a contact force is a force applied to a body by another body that is in contact with it.
ex →An apple falling down from a tree is one of the best examples of non-contact force.
An apple falling down from a tree is one of the best examples of non-contact force.Iron pins attracted in the presence of a magnet bar without any physical contact.
An apple falling down from a tree is one of the best examples of non-contact force.Iron pins attracted in the presence of a magnet bar without any physical contact.Falling of raindrops on earth is also an example of non-contact force.
→ Releationship between "F" & "p"
PREESURE = FORCE PER UNIT ÷ AREA
P = F ÷ A
→ WHY SPORTEN USE SPIKES ??
→ Sportsman use shoes with spikes to increase the force of friction between the shoes and the ground. The increased force of friction give them a better grip while running.
Answer:
Write a functions and composition of blood