Forces and energy (Year 8)

Question 1

what type of surface has a large amount of friction

Answer 1

rough surface

Question 2

what type of surface has a small amount of friction

Answer 2

smooth surfaces

Question 3

what is the unit used to measure force

Answer 3

newton

Question 4

A box is pulled to the right with 6 N and to the left with 6 N. The resultant force is

Answer 4

zero newtons

Question 5

The force of friction is ALWAYS in this direction

Answer 5

opposite to the direction of motion

Question 6

forces are…

Answer 6

Pushes or Pulls

Question 7

what is a resultant force

Answer 7

the overall value of the forces acting on an object after considering the direction of the forces

Question 8

what is an unbalanced force

Answer 8

when the forces are NOT EQUAL to each other in a particular direction. Gives a resultant force

Question 9

what is a balanced force

Answer 9

the force that does NOT change an object’s motion because the forces are equal and opposite so therefore cancel each other out

Question 10

mass

Answer 10

the measure of the amount of matter in an object

Question 11

is gravity a non contact force

Answer 11

yes

Question 12

what is terminal velocity

Answer 12

the fastest speed reached by a skydiver when the weight and drag forces become equal

Question 13

define upthrust force

Answer 13

force that allows an object to float in a fluid.

Question 14

Acceleration is equal to

Answer 14

force divides by a mass

Question 15

define thrust

Answer 15

this is the push of an engine and acts in the forward direction

Question 16

what is tension

Answer 16

the force inside a stretched rope , string or reaction. it acts in a direction to return the object to its original shape

Question 17

forces can cause 3 things to happen, What are they ?

Answer 17

1. can cause a change in state
2. can cause a change in direction
3. can cause a change in speed

Question 18

what device is used to measure a force

Answer 18

newton meter

Question 19

name the 8 forces that we have learnt

Answer 19

friction
drag or air resistance
tension
weight
thrust
lift
normal contact
upthrust

Question 20

simplify
weight= mass x gravitational field strength

Answer 20

w = mg

Question 21

what is measured in meters per second squared. It tells you how quickly the object is changing its speed, while it is …

Answer 21

acceleration

Question 22

what is deceleration

Answer 22

If it is slowing down, it is losing speed every second. This is called a deceleration (be careful with the spelling).

Question 23

mass is equal to …

Answer 23

forces divided by acceleration

Question 24

force is equal to …

Answer 24

mass multiplied by acceleration

Question 25

what is the value of the gravitational field strength on the earth

Answer 25

10 N/kg

Question 26

define weight

Answer 26

the measure of the amount of gravity pulling down on an object. It depends on the gravitation field strength

Question 27

What MUST you include when representing forces on a diagram

Answer 27

arrow, label, value, unit

Question 28

The forces of weight ALWAYS acts in what direction

Answer 28

Straight down

Question 29

what is the unit for mas

Answer 29

kg

Question 30

what are the units for gravitational field strength

Answer 30

N/kg