Forces

Question 1

Resultant force:

Answer 1

mass x acceleration

Question 2

SI Base units for resulant force:

Answer 2

kgms^-2

Question 3

Define the newton

Answer 3

force that will give a mass of 1kg an acceleration of 1 ms^-2

Question 4

Define weight:

Answer 4

the gravitational force acting on an object through its centre of mass

Question 5

Equation for weight:

Answer 5

mass x gravitational field strength

Question 6

Define friction:

Answer 6

the force that arises when 2 surfaces rub against each other

Question 7

Define drag:

Answer 7

the resistive force on an object travelling through a fluid

Question 8

Define tension:

Answer 8

the force within a stretched cable or rope

Question 9

Define upthrust:

Answer 9

the upward buoyancy force acting on an object when it’s in a fluid

Question 10

Define normal contact force:

Answer 10

the force arising when an object rests against another object acting at a 90 angle to the plane of contact

Question 11

What 3 factors does the magnitude of drag depend on?

Answer 11

1) Speed
2) Structure/Shape of object
3) Density of fluid

Question 12

What is drag proportional to?

Answer 12

speed squared

Question 13

When will drag stop increasing?

Answer 13

when equal to weight

Question 14

What practical measures terminal velocity?

Answer 14

dropping ball through viscous liquid

Question 15

Equation for moments:

Answer 15

force x perpendicular distance to pivot

Question 16

What are equal to 0 if an object is in equilibrium?

Answer 16

sum of forces and sum of moments

Question 17

What is a couple?

Answer 17

two equal and opposite forces acting a distance apart

Question 18

What is a torque?

Answer 18

turning effect

Question 19

Define centre of mass:

Answer 19

where the entire weight of an object appears to act

Question 20

Density equation:

Answer 20

mass/volume

Question 21

What is the practical to find density?

Answer 21

submerging and object in a eureka can (irregular) or measuring objects dimensions (regular)

Question 22

Pressure equation:

Answer 22

force/area

Question 23

Pressure in fluids equation:

Answer 23

density x height x gfs

Question 24

What is Archimede’s principle?

Answer 24

the upthrust exerted on a body immersed in fluid, whether partially or fully submerged is equal to the weight of the fluid displaced

Question 25

What are the 3 steps to finding upthrust?

Answer 25

1) Find objects volume
2) Find mass of water displaced using density
3) Find the weight of water displaced