Gravitation + Elasticity Flashcards
What are Kepler’s laws
- All planets move around the sun in an elliptical orbit having the sun at any one focus
- A line joining the sun and planet sweeps out equal areas in equal time
- The square of the time is directly proportional to the cube of the mean distance
What is gravity
The force by which the earth attracts a body towards its centre
What is acceleration due to gravity
The rate of increase of velocity of a body freely falling towards earth
What is a gravitational field
The sapce around the attracting body where the gravitational force of that body can be experienced
What is gravitational potential
Thw work done in bringing a unit mass form infinity to a point in the gravitational feild
What are the consequences of escape velocity
- Moon has no atmosphere
- Black holes are very small
What is a derforming force
An external force which causes a change in size or shape when applied on the body
What is elasticty
The property of a body of recovring its original shape or size after the removal of a deforming force
What is stess
The internal restoring force acting per unit area
What is strain
The change occured in unit size of the body
What is Hooke’s law
if the strain is small, then stress is directly proportional to the strain
What are the three stress
- Longitudinal
- hydrostatic
- tangential/ shearW
What are the three strain
- Longitudinal
- volume
- shearing
What are the three moduli
- Young’s modulus
- Bulk modulus
- Modulus of rigidity
