forces

Question 1

hooke’s law

Answer 1

the change in length of a material is directly proportional to the force applied on it, provided that the limit of proportionality is not exceeded

Question 2

archimedes’ principle

Answer 2

states that when a body is immersed in a fluid, it is buoyed by an upthrust equal in magnitude and opposite in direction to the weight of fluid displaced by the body

Question 3

upthrust

Answer 3

upward force exerted by a fluid on an object submerged fully or partially in the fluid due to the difference in pressure exerted by the fluid on the upper and lower surfaces of the object. it acts through the centre of mass of the displaced fluid and is equal in magnitude and opposite in direction to the weight of fluid displaced by the body

Question 4

moment of a force

Answer 4

the product of the magnitude of the force and the perpendicular distance of the point from the line of action of the force.

Question 5

moment of a torque due to a couple

Answer 5

the product of the magnitude of one of the forces and the perpendicular distance between the lines of action of the forces.

Question 6

couple

Answer 6

pair of forces acting on the same body (or system) that
are equal in magnitude and opposite in direction
whose line of action do not coincide
which tends to produce rotation only

Question 7

principle of moments

Answer 7

when a body is in rotational equilibrium, the sum of clockwise moments about any point must be equal to the sum of anticlockwise moments about the same point

Question 8

conditions for eqm

Answer 8

the vector sum of forces exerted on it must be zero/resultant force in any direction is zero
the resultant torque on it must be zero about all axes/resultant moment at any point is zero