Mechanics and Materials

Question 1

Moment about a point

Answer 1

Force multiplied by the perpendicular distance from the line of action of the force to the point

Question 2

Couple

Answer 2

• pair of coplanar forces
• equal in magnitude
• opposite directions

Question 3

Principle of moments

Answer 3

For an object in equilibrium, sum of anticlockwise moments about a pivot is equal to the sum of clockwise moments

Question 4

Acceleration time graphs

Answer 4

Area under is change in velocity

Question 5

Velocity time graphs

Answer 5

• Gradient is acceleration
• Area under is displacement

Question 6

Displacement time graphs

Answer 6

Gradient is velocity

Question 7

SUVAT can only be used when…

Answer 7

there is uniform acceleration

Question 8

Free Fall

Answer 8

when object experiences acceleration g

Question 9

Friction

Answer 9

• force which opposes the motion of an object
• convert KE to other forms of energy

Question 10

Terminal speed

Answer 10

Occurs when frictional forces are equal to driving forces

Question 11

Newtons 1st Law

Answer 11

An object will remain at rest or at a constant velocity until it experiences a resultant force

Question 12

Newtons 2nd Law

Answer 12

Acceleration of an object is directly proportional to resultant force
F = ma

Question 13

Newtons 3rd Law

Answer 13

For each force experienced by an object, the object exerts an equal and opposite force.

Question 14

Momentum

Answer 14

• Product of mass and velocity of an object
• Always conserved

Question 15

Impulse

Answer 15

Change in momentum

Question 16

Force-Time graph

Answer 16

Area is change in momentum

Question 17

Elastic Collision

Answer 17

Both momentum and KE are conserved

Question 18

Inelastic Collision

Answer 18

Only momentum is conserved, KE converted into other forms

Question 19

Efficiency

Answer 19

Measure of how efficient a system transfers energy

Question 20

Principle of conservation of energy

Answer 20

Energy cannot be created or destroyed

Question 21

Density

Answer 21

Mass per unit volume

Question 22

Hookes Law

Answer 22

Extension is directly proportional to the force applied given that environmental conditions are kept constant