forces 1 and 2 AUTUMN TEST

Question 1

a vector has…
a scalar has…

Answer 1

magnitude and direction
just magnitude

Question 2

… cannot be negative but… can

Answer 2

scalars
vectors

Question 3

examples of scalar

Answer 3

speed
distance
time
mass
energy

Question 4

examples of vector

Answer 4

velocity displacement acceleration force momentum

Question 5

what is scalar

Answer 5

can be measured with a number (magnitude)

Question 6

what is a vector quantity

Answer 6

• measured with a number
• BUT ALSO
• has a direction

Question 7

gravity-the larger the… the stronger the… the greater the…

Answer 7

mass
field
attraction

Question 8

weight calc

Answer 8

weight = mass x gravitational field strength

Question 9

weight is measured using a… by…

Answer 9

force meter/ calibrated spring-balance
by the weighing scales measuring the force you exert then divides by 10 to get the mass

Question 10

gravitational field strength on earth

Answer 10

9.8

Question 11

what happens to mass and weight of the same person on two different planets

Answer 11

mass stays the same
e=weight is different bc gfs is different

Question 12

skydiver example of resultant forces

Answer 12

1. initially there is no air resistance so only force acting on him is weight = accelerates
2. air resistance increases, resultant force from weight decreases = acceleration decreases
3. eventually equal and balance , so no resultant force = no acceleration

Question 13

work done =

Answer 13

work done = force x distance

Question 14

elastic deformation

Answer 14

the object returns to its original shape when the load has been removed

Question 15

plastic deformation

Answer 15

the object does not return to its original shape when the load is removed, this can be a spring when pulled to far

Question 16

hooke’s law

Answer 16

the extension of an elastic object is directly proportional to the force applied, provided that the limit of proportionality is not exceeded

Question 17

hooke’s law calc

Answer 17

force = spring constant x extension
F = kx

Question 18

hooke’s law: why does the graph stop being linear

Answer 18

• the limit of proportionality has been reaches so no longer obeys hooke’s law
• turns to plastic behaviour

Question 19

hooke’s law: if the graph is just linear with no non linear end section…

Answer 19

.. the material is brittle, so snaps instead of stretching after the elastic limit

Question 20

work done (spring) calc

Answer 20

work done = 1/2 x spring constant x extension squared

Question 21

work done on the spring =

Answer 21

= the elastic potential energy stored

Question 22

if an object is moving in a circular motion, the acceleration… because…

Answer 22

increases because changing velocity is defined as acceleration so the change in direction means it accelerates

Question 23

speed equation

Answer 23

speed = distance / time

Question 24

displacement time graphs:
- sharper gradient means…
- negative gradient means…
- horizontal line means…
- curved line means..

Answer 24

sharper gradient = faster speed
negative gradient = returning back to starting point
horizontal line = stationary
curved line = velocity is changing

Question 25

velocity-time graphs:
gradient is…
sharper gradient means…
negative gradient means…
horizontal line means…
0 velocity means…
curved line means…

Answer 25

gradient is acceleration
sharper gradient is greater acceleration
negative gradient is deceleration
horizontal line is constant speed
0 velocity is stationary
curved line means acceleration is changing

Question 26

newtons first law

Answer 26

an object has a constant velocity unless acted on by a resultant force

Question 27

newtons second law

Answer 27

the acceleration of an object is proportional to the resultant force acting on the object, and inversely proportional to the mass of the object

Question 28

equatino linking force acceleration and mass

Answer 28

force = mass x acceleration

Question 29

inertia

Answer 29

the measure of how difficult it is to change the velocity of an object

Question 30

newtons third law

Answer 30

whenever two objects interact, the forces they exert on each other are equal and opposite