Forces

Question 1

1. What is a scalar quantities and some examples?

Answer 1

• has magnitude and no direction.

- time ,mass, speed ,temperature etc..

Question 2

2.What is a vector quantity and some examples?

Answer 2

• has magnitude and direction.

- velocity, displacement ,force

Question 3

3. How would you draw vectors?

Answer 3

• magnitude=length of arrow.

- way it’s pointing=direction

Question 4

4. What is the definition of forces and what do we measure it in?

Answer 4

• a push or pull, that acts on an object, due to its interaction with another object.
• measured in Newtons.

Question 5

5. What are contact and non-contact forces?

Answer 5

• contact forces are when two objects have to be physically touching.
• non-contact forces are when the objects do not have to be physically touching.

Question 6

6. What are examples of contact forces?

Answer 6

-friction ,tension ,air resistance

Question 7

7. What are normal contact forces?

Answer 7

-two forces that are acting equal and opposite.

Question 8

8. What are examples of non-contact forces and how do they decrease?

Answer 8

• gravitational, magnetic, electrostatic.

- when they get further apart.

Question 9

9. How do you calculate weight?

Answer 9

-mass x gravitational field strength

Question 10

10. What are free body diagrams?

Answer 10

-they show all the forces acting on an object.

Question 11

11. What is a resultant force?

Answer 11

-they show the overall force of an object.

Question 12

12. How do you calculate a resultant force?

Answer 12

• you do right force-left force (to get the horizontal component).
• you do up force-down force (to get vertical component).
• then you add the vertical and horizontal component to get the resultant force.

Question 13

13. What does equilibrium mean?

Answer 13

-when the resultant force is 0, the objects are in equilibrium.

Question 14

14. What are the two types of deformations?

Answer 14

• elastic (when the object goes back to its original shape).

- inelastic (when the object doesn’t go back to its original shape.

Question 15

15. How can materials be deformed?

Answer 15

-by compressing, bending or stretching them.

Question 16

16. What is extension?

Answer 16

-the increase in the length of the spring when its stretched.

Question 17

17. Why does the spring not fall off when adding a mass onto it?

Answer 17

-it has an equal but opposite force acting on it.

Question 18

18. What is the equation for spring constant?

Answer 18

-F=ke (force=spring constant x extension)

Question 19

19. What does a force extension graph look like?

Answer 19

-it goes from left to right upwards.

Question 20

20. What is Hooke’s Law?

Answer 20

-the fact that force and extension are directly proportional.

Question 21

21. What is the limit of proportionality/elastic limit?

Answer 21

• when the line starts to curve and Hooke’s Law no longer applies.
• after this limit, the object may not go back to its original shape.

Question 22

22. What is a spring constant?

Answer 22

-a measure of how many newtons it takes to stretch the object by 1 metre.

Question 23

23. What is the equation for elastic potential energy?

Answer 23

-Ee=1/2ke squared

Question 24

24. What is elastic potential energy?

Answer 24

-it is the energy transferred to an object as its stretched.