CP8

Question 1

How can objects interact with eachother?

Answer 1

By exerting forces on each other.

Question 2

What are contact forces?

Answer 2

Contact forces are forces that are between objects that are touching.

Question 3

What is gravity?

Answer 3

A force that occurs between any two objects that have mass.

Question 4

What are action-reaction forces?

Answer 4

A pair of forces acting on an object. These forces are always the same size, in opposite directions, and acting on different objects.

Question 5

What is the difference between action-reaction forces and balanced forces?

Answer 5

Action-reaction forces act on two different objects whereas balanced forces react on a single object.

Question 6

What is a force field?

Answer 6

It is the space around an object where it can affect other objects.

Question 7

When are the forces of an object equal?

Answer 7

When the forces are equal in size but in opposite directions. This makes the resultant force zero.

Question 8

What is the resultant force and how is it found out?

Answer 8

The total force that results from two or more forces acting upon a single object. It is found out by adding together the forces, taking into account their directions.

Question 9

What is the resultant force of an airplane when flying at a constant velocity?

Answer 9

When flying at a constant velocity, the horizontal forces and vertical forces on it are balanced. The resultant force on the airplane is zero.

Question 10

What is a free body force diagram?

Answer 10

A diagram of an object showing all the forces acting upon it and the size and direction of those forces.

Question 11

What is a scale diagram?

Answer 11

A way of working out the resultant forces by drawing a diagram where the length of the arrows represents the sizes of the forces.

Question 12

How can you use a scale diagram to figure out the resultant force?

Answer 12

1. Draw arrows at the correct angles to represent the forces. The length of the arrow should represent the size of the force.
2. Draw lines to make the parallelogram
3. The resultant force is the diagonal of the parallelogram. Measure this arrow to work out the size of the resultant force.

Question 13

How can a scale diagram be used to resolve forces?

Answer 13

1. Draw a force arrow to scale at the correct angle
2. Draw a rectangle with the sides in the directions you are interested in (e.g. horizontal and vertical)
3. The resolved forces are the sides of the rectangle