P8 Forces In Balance

Question 1

What is displacement?

Answer 1

Distance without change of direction.

Question 2

What are the vectors?

Answer 2

Acceleration, gravitational field strength, force, momentum, weight, velocity + displacement.

Question 3

What are the scalars?

Answer 3

Speed, distance, time, mass, energy + power.

Question 4

What is a scalar?

Answer 4

Physical quantities that have size, no specific direction.

Question 5

What is the size of a quantity?

Answer 5

Its magnitude.

Question 6

What is a vector?

Answer 6

Physical quantities that have direction.

Question 7

What does a vector have?

Answer 7

Magnitude + direction.

Question 8

What does a scalar have?

Answer 8

Magnitude only.

Question 9

What is Newton’s third law of motion?

Answer 9

When 2 objects interact with each other, exert equal + opposite forces on each other.

Question 10

What is the unit of force?

Answer 10

The newton (abbreviated as N).

Question 11

What is a resultant force?

Answer 11

Single force that has same effect as all forces acting on an object.

Question 12

What does Newton’s first law state?

Answer 12

If force acting on an object are balanced, resultant force on object is 0.
If object is at rest, stays stationary.
If object moving, keeps moving with same speed and in same direction.

Question 13

What is the moment of the force?

Answer 13

Turning effect of force.

Question 14

What can the moment of the force be increased by?

Answer 14

Increasing size of force.

Using spanner with long handle.

Question 15

What is the load of the object?

Answer 15

Weight of the object.

Question 16

What is the effort?

Answer 16

Force person applies to crowbar.

Question 17

How can you work out the moment of a force?

Answer 17

Using the equation:
Moment, M (newton metres, N m)= force, F (newtons, N) * perpendicular distance from line of action of force to pivot, d (metres, M).

Question 18

What is the centre of mass of an object?

Answer 18

Point at which its mass can be thought of as being concentrated.

Question 19

How can you find the centre of mass of a symmetrical object?

Answer 19

For flat symmetrical object centre of mass along axis of symmetry.

Question 20

What does the principle of moments state?

Answer 20

Sum of all clockwise moments about any point = sum of all anticlockwise moments about that point.

Question 21

What equipment do you need to test an incline?

Answer 21

1) Use newton-meter to measure weight of trolley + the force, add weights to trolley to find out how force changes as weight of trolley increased.
2) Repeat test with board at alternative angle to laboratory bench.
3) Record all measurements in table, + plot graph of results.
4) Write down conclusions made from graph about relationship between force + weight.