FORCE & IT'S EFFECTS
Force is defined by
a. Magnitude
b. Direction
c. Magnitude and direction both
d. Depends upon the type of force applied
Which of these is a contact force?
a: Gravitation
b: magnetic
c: friction
d: electrostatic
c: friction
What is the SI unit of pressure Pascal also called?
N/m2
Liquid pressure increases with depth and atmospheric pressure decreases with height.
Identify the effects of force in the following:
a: Rolling a chapati
b. Rolling ball comes to rest
c. Car turning around a round about
a: Change in shape.
b: causes a body in motion to stop also change in speed.
c: change in direction.
Identify the type of force acting :
a: Leaf falling from a tree
b: Hitting a ball with a bat
c: Walking
d: A sky diver opens the parachute and moves upwards for sometime
a: Gravitational
b: Muscular
c: Friction
d: Upthrust or buoyancy
Why is it that Camels can easily walk on sand compared to you or me? What is the physics behind it?
Camels have broad feets - which increases the area of contact- and force is distributed over larger area and hence reduces the pressure on sand so camels can walk easily on sand.
Jaipur or Goa - Which one do you think will have low atmospheric pressure? Give reason.
Goa is a coastal region- climate is extremely humid- water vapour content is more in air- so humid air being light- it exerts less pressure on us.
Seeta and Geeta are pushing a carton box from left and right respectively. If the box moves towards Seeta then which of the following is TRUE?
a:Magnitude of force applied by Seeta is more than Geeta
b:Magnitude of force applied by Geeta is more than Seeta
c:Magnitude of force applied by both is equal
d: Actually the box does not move at all.
b:Magnitude of force applied by Geeta is more than Seeta
(As body moves in the direction of greater force)
A heavy car is lifted with the help of a strong magnet. When the car is hanging from the crane- what are the forces acting on it? What types of forces are these- contact or non- contact?
Magnetic and gravitational forces- both are non contact forces.
It is easier to hammer a sharp nail into the wall than a blunt one- why?
As sharper nail has less area of contact- so the force acts on small area- hence pressure is more and it easily fixes onto the wall.
Some people who climb mountains have reported bleeding from nose. What could be the reason?
At high altitudes the atmospheric pressure is very low- so pressure exerted by blood in our body is more than the outside pressure hence it can cause bursting of blood vessels- leading to bleeding.
Anita is an archer shooter. She shoots an arrow in the air horizontally. However, after moving some distance, the arrow falls to the ground. Name the initial force that sets the arrow in motion. Explain why the arrow ultimately falls down.
Anita puts muscular force to stretch the string- this is the initial force acting on the arrow when it is released and then because of gravitational force it comes down towards after some time.
Give 2 examples of each- contact force & non-contact force from your daily life.
open answers
Calculate the pressure on a man's foot when a woman who weighs 520 N steps on his foot with her heel, which has an area of 0.001 m2 with all of her weight.
P = F / A
P = 520 N/ 0.001 m2 = 52000 Pa