MECHANICS 2

Question 1

INSTANTANEOUS SPEED

Answer 1

speed of an object at a given moment in time

Question 2

MOMENT

Answer 2

turning effect due to a single force - force x perpendicular distance from pivot (Nm) vector

Question 3

NEWTON

Answer 3

unit of force (N) 1N gives a mass of 1kg an acc of 1ms-2

Question 4

PLASTIC DEFORMATION

Answer 4

object will not return to its original shape when the deforming force is removed- it becomes permanently distorted

Question 5

POLYMETRIC MATERIAL

Answer 5

material made of many smaller molecules bonded together often in tangled long chains, often exhibit very large strains eg 300%

Question 6

POWER (P)

Answer 6

rate of doing work (W) scalar

Question 7

PRESSURE (p)

Answer 7

force per uniot area (Pa/ 1Nm-1) scalar

Question 8

PRINCIPLE OF MOMENTS

Answer 8

for a body in rotational equilibrium the sum of the clockwise moments equals the sum of the anticlockwise moments

Question 9

RESULTANT FORCE

Answer 9

overall force when combining two or more forces

Question 10

SCALAR

Answer 10

physical property with magnitude but not direction

Question 11

SPEED (s)

Answer 11

distance travelled per unit time (ms-1) scalar

Question 12

SPRING CONSTANT

Answer 12

force per unit extension

Question 13

STOPPING DISTANCE

Answer 13

thinking distance + braking disance

Question 14

STRESS

Answer 14

force per unit cross sectional area (Pa)

Question 15

STRAIN

Answer 15

extension per unit length (ratio)

Question 16

TENSILE FORCE

Answer 16

2 equal & opposite forces acting on a wire in order to stretch it ( when both forces have value T the tensile force is also T not 2T)

Question 17

TENSILE STRESS

Answer 17

tensile force per unit cross sectional area

Question 18

TENSILE STRESS

Answer 18

tensile force per unit cross sectional area