Mechanics

Question 1

What is a scalar quantity

Answer 1

A quantity that only has a magnitude and no direction
e.g. speed, mass, distance, temperature, time, power, energy

Question 2

What is a vector quanity

Answer 2

A quantity that has magnitude and direction
e.g. velocity, displacement, acceleration, force, momentum

Question 3

What are coplanar forces

Answer 3

Forces that act in the same plane

Question 4

What does forces being in equilibrium mean

Answer 4

It means the resultant force is 0
This means the object is stationary or at constant velocity

Question 5

How can you check if 3 forces are in equilibrium

Answer 5

If the 3 coplanar forces are in equilibrium, they should form a closed triangle when you draw them tip to tail on a vector diagram

Question 6

How do you resolve a vector

Answer 6

By splitting it into 2 perpendicular components

Question 7

What are the force components when resolving forces on an inclined plane

Answer 7

Component parallel to the plane = Wsinθ
Component perpendicular to the plane = Wcosθ

Question 8

What is a moment

Answer 8

moment = force x perpendicular distance from the point to the line of action of the force
moment = Fd

Question 9

How can the resultant moment be zero

Answer 9

For a system to be in equilibrium, the sum of clockwise moments must equal the sum of anti-clockwise moments