Mechanics

Question 1

What is a scalar

Answer 1

Physical quantity with a magnitude, but no direction.

Eg: time, mass, length, area, volume, energy, charge, pressure, charge

Question 2

What’s a vector

Answer 2

Physical quantity that has both magnitude and direction.

Eg: force, velocity and electric field

Question 3

Define resultant

Answer 3

A single vector that indicates magnitude and direction of the combine effect of two or more vectors

Question 4

Bearing

Answer 4

Direction given as angle relative to north in clockwise direction

Question 5

Define force

Answer 5

Any kind of push or pull on an object in an attempt to change object’s state of rest or motion

Question 6

Contact force

Answer 6

Force exerted by objects on each other when they touch or connect with one another

Question 7

Applied force

Answer 7

Force externally applied to an object

Question 8

Normal force

Answer 8

contact force exerted by a surface on an object perpendicular to that surface

Question 9

Tension

Answer 9

Force exerted by an object that can stretch

Question 10

Friction

Answer 10

contact force that a surface exerts on an object parallel to the surface and opposite to the direction of motion or attempted motion

Question 11

Static frictional force

Answer 11

Friction force exerted on an object that is not being set in motion.

Question 12

Kinetic frictional force

Answer 12

Friction force that an object experiences when it moves over a surface

Question 13

Non-contact force

Answer 13

Forces that objects exert on each other over a distance without touching each other

Question 14

Magnetic force

Answer 14

attractive or repulsive force between magnetic objects

Question 15

Electrostatic force

Answer 15

attractive or repulsive force between charges (charged objects)

Question 16

State Newton’s first law of motion

Answer 16

An object continues in a state of rest or uniform velocity unless it is acted upon by an external net force

Question 17

What is inertia

Answer 17

Property of a body that enables it to resist change in its motion

Question 18

State Newton’s second law of motion

Answer 18

When a net force is applied to an object of a certain mass it accelerates in the direction of the net force. The objects acceleration is directly proportional to the net force applied to the object and inversely proportional to the object’s mass

Question 19

What is uniform motion

Answer 19

Motion at a constant speed in a straight line

Question 20

Net force or resultant force

Answer 20

Vector sum of all the forces acting on an object

Question 21

Superposition

Answer 21

Addition of two or more effects at a single point in space

Question 22

State Newton’s third law of motion

Answer 22

When object A exerts a force on object B, object B simultaneously exerts an opposite directed force of equal magnitude on object A

Question 23

State Newton’s law of universal gravitation

Answer 23

Every particle in the universe exerts a force of attraction on every other particle. The force exerted by one particle on another is directly proportional to the product of their masses and inversely proportional to the square of the distance between them.