kinematic and dynamic

Question 1

average speed

Answer 1

the total distance travelled by an object divided by the total time taken

Question 2

instantaneous speed

Answer 2

the speed of an object measured over a very short period of time

Question 3

displacement

Answer 3

the distance travelled in a particular direction; it is a vector quantity

Question 4

vector quantity

Answer 4

a quantity with both magnitude and direction

Question 5

scalar quantity

Answer 5

a quantity with magnitude only

Question 6

velocity

Answer 6

an object’s speed in a particular direction; it is a vector quantity

Question 7

acceleration

Answer 7

the rate of change of an object’s velocity; the unit of measure is ms^-2

Question 8

constant acceleration

Answer 8

when the change in velocity of an object is the same in the same time period

Question 9

tangent

Answer 9

a straight line that touches a curve but does not cross it at a point

Question 10

free fall

Answer 10

when an object accelerates due to gravity in the absence of any other force such as air resistence

Question 11

component

Answer 11

the effect of a vector along a particular direction

Question 12

Newton’s second law of motion

Answer 12

resultant force is proportional (ore equal) to mass x acceleration

Question 13

inertia

Answer 13

a measure of how difficult it is to change the velocity of an object, or change its speed or direction. It is a measure of the mass of an object; a massive object has large inertia

Question 14

weight

Answer 14

the force on an object caused by a gravitational field acting on its mass

Question 15

friction

Answer 15

a resistive force when two surfaces are in contact and tending to slide over one another

Question 16

uniform motion

Answer 16

the natural state of motion of an object-uniform velocity, constant speed and direction

Question 17

Newton’s first law of motion

Answer 17

an object will remain at rest or in a state of uniform motion unelss a resultant force acts on it

Question 18

resultant force

Answer 18

the single force that has the same effect as all of the forces acting on an object

Question 19

terminal velocity

Answer 19

the maximum velocity reached by an object falling under gravity or accelerated by a constant force

Question 20

resistive force

Answer 20

a backwards force in the opposite direction to movement caused by fricton or some other viscous force

Question 21

drag

Answer 21

a force that resists the movement of an object through a fluid

Question 22

contact force

Answer 22

the force at right angles to a surface when two objects are in contact

Question 23

upthrust

Answer 23

the force upwards in a liquid or gas caused by the pressure in the gas or liquid

Question 24

Newton’s third law of motion

Answer 24

when two bodies interact, the forces they exert on each other are equal size and opposite direction

Question 25

base units

Answer 25

defined units of the SI, system from which all other units are derived

Question 25

derived units

Answer 25

units that are combinations of the base units of the SI system

Question 25

newton

Answer 25

the force that will give a 1 kg mass an acceleration of 1ms^-2 in the direction of that force

Question 25

homogenous

Answer 25

equations with the same base units on each side are homogenous