1.
A skier travels 3000m in 93s. Calculate
her speed.
S = d ÷ t = 3000m ÷ 93 s = 32.26 m/s
2.
A cyclist travels 1000m in 75s.
Calculate his speed.
S = d ÷ t = 1000m ÷ 75 s = 13.33 m/s
3.
A train travels 1200m in 80s. Calculate
its speed.
S = d ÷ t = 1200m ÷ 80 s = 15 m/s
4.
A mouse walks 10m in 20s. Calculate its
speed
S = d ÷ t = 10m ÷ 20s = 0.5 m/s
5.
Concord travels at 660m/s (twice the
speed of sound in air at 00C). How far will it travel in one minute?
d = s x t = 660 m/s x (1 x
60s) = 39600 m = 39.6 km
6.
To leave the Earth’s gravitational
field a space vehicle must reach escape speed which is about 18 km/s. How high
will the rocket be 34s after lift off? Has any human left the influence of the
Earth’s gravitational field?
d = s x t = 18 km/s x 34s =
612 km
No – as the moon orbits the
Earth
7.
The term light year is often misused.
It is the distance light travels in one year. Given that light travels at 300
000 000m/s (3x 108 m/s) how far is that light year?
1 light year or d = s x t = 3
x 108 m/s x (365.25 days x 24 hr x 60min x 60s) = 9.47 x 1015 m
If you could travel at the speed of light (not possible) how
long would it take you to travel that light year?
For you no time would pass. For those on earth 1
year would pass.
8.
A car travels at 35m/s on a motorway.
How long will it take to travel that light year? (In years please)
t = d÷s = 9.47 x 1015 m ÷ 35 = 2.7 x 1014 s =
2.7 x 1014 s ÷ (356.25 days x 24 hr x 60 min x 60 s) = 85.6
million years
9.
A waiter walks at 2m/s. How long will
it take him to reach your table 15m away and will your soup be cold when he
gets there?
t = d÷s = 15 ÷ 2 m/s = 7.5 s Yes,
its Gazpacho
10. A
water ripple travels at 6 cm/s. How long will it take to travel 1m?
t = d÷s = 1 ÷ 6/100 m/s = 16.67s
11. The
average speed of a sprinter is about 11m/s. How long does she take to run the
100m?
t = d÷s = 100 ÷ 11 m/s = 9.09 s (a new world record!)
Compare this speed with a1500m runner
who turns in a very respectable time of 3m 50s.
s = d÷ t = 1500m ÷ 230s s = 7.5 m/s
Why is there a difference? Oxygen debt due to build up of lactic acid in muscles
12. A
tennis player’s serve is measured at 50m/s. How long will it take to travel the
length of a tennis court (23.8m)
t = d÷s = 23.8m ÷ 50 m/s = 0.48 s
The Steady Earth
I.
The Earth has a diameter of 12756km at
the equator. Given it takes 23hrs and 56 minutes to revolve once how fast would
you be travelling at the equator? (In m/s and km/h please.)
Distance travelled =
circumference of Earth = pd = 3.142 x 12756 = 40 100 km = 4.01 x107 m
Time taken = 23 hrs 56 min = {(23x60) + 56}min x 60s=
86160s
Speed = distance ÷ time = 40100km ÷ 23.93hr = 1676 km/h
Speed = distance ÷ time = 4.01 x 107 m ÷ 86160s = 465.4 m/s
What stops you flying off into space? Gravity
We live some way north of the equator,
do we travel as fast? No as we travel less distance in
one rotation.
How fast would you be spinning if you
were at the North Pole? 0
II.
The average distance from our planet to
the sun is 149,503,000 km. The earth orbits the sun
once every 365.25 days. How fast are we all going?
Distance travelled =
circumference of Earth’s orbit = 2pr = 3.142 x 2 x149 503 000km
= 4.697 x 109 km =
4.697 x 1012m
Time taken = 365.25 days= 365.25 x 24 = 87000 hr = 87000 x
60min x 60s= 3.132 x 108s
Speed = distance ÷ time = 4.697 x 109 km ÷ 87000 hr = 54 000 km/h
Speed = distance ÷ time = 4.697 x 1012m ÷ 3.132 x 108s = 1.5
x104 m/s = 15 km/s = 465.4 m/s
(Assume the orbit is
circular, it's not quite, we are slightly closer to the sun in January than
July; if so why is it so cold? The seasons are caused by
the tilt of the earth’s axis of rotation to the plane of its orbit)
III.
The sun and the whole solar
system are on the move around the centre of our galaxy that is called The Milky
Way. We are moving towards the constellation of Hercules at a leisurely 20.1
km/s. At this speed how long would it take to travel around the Earth?
Time = Distance ÷ speed = 40 100 km ÷ 20.1 km/s = 1995 s = 33 min
IV.
This is nothing the whole
of our galaxy is on the move as the universe expands. We all move outward
towards the constellation of Leo (only from our point of view) at 600km/s.
How far have we travelled since you started this worksheet? 360 000km… but then it only took me 10 minutes
Velocity = distance/time distance = speed x time time = distance/velocity
Diameter of a circle = twice its radius
(r) circumference = 2pr p = 3.142