SAMPLE ONLY SAMPLE ONLY SAMPLE ONLY

For FULL presentation click HERE >> www.warnescience.net

Falling Bodies (Vertical Motion)

K Warne

SAMPLE ONLY SAMPLE ONLY SAMPLE ONLY

For FULL presentation click HERE >> www.warnescience.net

Mass & Weight

Mass (kg):

• This is a measure of the

amount of matter

(number of kilograms)

that makes up a body.

Weight (N):

• This is the force of gravity

exerted on a body’s mass by

the earth (planet).

Fg

1 kg

1 kg

1 kg

G10 Revision

SAMPLE ONLY SAMPLE ONLY SAMPLE ONLY

For FULL presentation click HERE >> www.warnescience.net

98 N

Falling ObjectsTwo different object with different masses will FALL at the same RATE.

• The force of gravity on 1kg of mass is 9.8 N.

• Each unit of mass has the same force on it!

• Each mass unit will have the SAME ACCELERATION.

1kg

9.8N

9.8kg1kg

9.8N

1kg

9.8N

1kg

9.8N

1kg

9.8N

1kg

9.8N

Weight = mass x 9.8

Force of

gravity on the

mass (N)

Amount of

matter in

the object

(kg)

Gravitational

acceleration

(m.s-2)

SAMPLE ONLY SAMPLE ONLY SAMPLE ONLY

For FULL presentation click HERE >> www.warnescience.net

Gravitational Field Strength

• The weight of a 5kg bag of sugar on each planet.

g = 9.8 N.kg-1 g = 3.8 N.kg-1

A gravitational field causes masses inside it to experience a

force of attraction.

Gravitational field strength = Gravitational Force per unit mass

g = F/m (N.kg-1)

g = 23.6 N.kg-1

5kg 5kg…..N ….. 5kg……….

SAMPLE ONLY SAMPLE ONLY SAMPLE ONLY

For FULL presentation click HERE >> www.warnescience.net

Finding “g” by Pendulum• The cotton is burnt to release the plumb bob.

• The vertical distance is measured to where the plumb bob …………………………...

• The distance is fallen in …………………….. ……………………………………………..

• Readings: …………….., …………………

S = ………………………

• The time is measured for ……… complete oscillations to give a ……………….. reading.

• If the time for 10 oscillations is 16,6s - the time for ¼ oscillation is …………………...

• If the distance fallen is …………..m.

• Acceleration or “g” can then be calculated.

a = …………………………………………….

s

SAMPLE ONLY SAMPLE ONLY SAMPLE ONLY

For FULL presentation click HERE >> www.warnescience.net

Motion of Falling objectTime (s) Displacem

ent (m)

Average

Velocity

Instantaneou

s Velocity

(m.s-1)

Accelerati

on (m.s-2)

0 0 0 0 10

5 5 10 10

20 10 20 10

45 15 30 10

4 80 20 40 10

5 125 25 50 10

6 180 30 60 10

1

2

3

SAMPLE ONLY SAMPLE ONLY SAMPLE ONLY

For FULL presentation click HERE >> www.warnescience.net

Fg =mg

1. Object about

to start

falling. V=0

W=mg

2. Object is

falling. V>0

Friction

a 9.8 m/s2

Friction=Fg

a= m/s2

TERMINAL VELOCITY

3. The object now

moves with

TERMINAL

VELOCITY.

An object is dropped from REST.

V = max

SAMPLE ONLY SAMPLE ONLY SAMPLE ONLY

For FULL presentation click HERE >> www.warnescience.net

• Falling objects …………………………….. at …………………..

• The velocity increases every second and the ……………………………… every second increases as well.

• The ……………………………… increaseswith every second that the object is falling.

• Each particle applies a small force on the object and the until the …………………… ……………………… to the downward force of gravity.

• There is …………………………. force and therefore no acceleration.

• The object will continue to move at …………. ………………….

• This velocity we call ……………………. The terminal velocity of an object is dependant on its size and shape.

Terminal velocity

From World Book © 2002 World Book, Inc., 233 N.

Michigan Avenue, Suite 2000, Chicago, IL 60601.

All rights reserved. World Book illustration by David

Cunningham

SAMPLE ONLY SAMPLE ONLY SAMPLE ONLY

For FULL presentation click HERE >> www.warnescience.net

G r a v i t y

Equations of motion for free fall and vertical

projectile motion

An object is in “…….. ……………” if:

• it is moving ….. or ……….. without ……………. other than ……………

• we ignore ………. ……………..

• we can substitute “g” for “a” in equations because the ………….. …………………. is gravity.

gsuv

gtuts

gtuv

2

2

1

22

2

SAMPLE ONLY SAMPLE ONLY SAMPLE ONLY

For FULL presentation click HERE >> www.warnescience.net

A ball falls freely from rest.a) velocity vs. time

b) displacement vs. time

c) acceleration vs. time

d) speed vs. time

e) distance vs. time

vt

xt

at

t

v x

t

a) b)c)

d) e)

+Consider only the period of free

fall and take upward direction as positive (+ve).

SAMPLE ONLY SAMPLE ONLY SAMPLE ONLY

For FULL presentation click HERE >> www.warnescience.net

A ball is thrown vertically upward and returns

to the throwers hand.a) velocity vs. time

b) displacement vs. time

c) acceleration vs. time

d) speed vs. time

e) distance vs. time

Consider only the period of free fall and take upward direction as positive (+ve).

vt

xt

xt

t

v s

t

a) b)c)

d) e)

SAMPLE ONLY SAMPLE ONLY SAMPLE ONLY

For FULL presentation click HERE >> www.warnescience.net

Hi -

This is a SAMPLE presentation only.

My FULL presentations, which contain a lot more more slides and other resources, are freely

available on my resource sharing website:

www.warnescience.net(click on link or logo)

Have a look and enjoy!

WarneScience