Movement
Forces
Motion
pressure
Extra Worked ?s
100
What do you need to calculate speed?
distance and speed
100
What is a force?
A pushing or pulling effect acting on an object.
100
What is the formula for moment?
Say the word equation and the symbol equation
moment = force x distance
m = F x s
100
What is the formula of pressure in word & symbol?
Pressure = Force / Area
p = F / A
100
What is the speed of a jet traveling 528 m in 4 seconds?
v = d / t
528m / 4s
v =132 m/s
200
A person is walking at a steady pace of 2.5 km/h.
He walks for 30 minutes.
How far does he walk?
v = d/t ; d = v x t
v = 2.5 hm/hr ; d = 0.5 hours
so...
d = 2.5 km/hr x 0.5
d = 1.25 km
200
What does an unbalanced force mean? Give an example of this.
An unbalanced force is when one force is larger than another acting on an object.
A car getting faster (accelerating) has an unbalanced force going forward.
200
What would you do to increase motion but make the force acting on the nut smaller?
You would increase the handle of the spanner.
A larger distance would increase the force of motion.
200
Which of the following would have a larger pressure?
An elephant whose foot has a large area
or
A woman's high heel whose area is very mall
The woman's high heel with a small area would have a larger pressure.
200
It takes Sam 15 minutes to travel to school, which is 16 km away. What is Sam's average speed in km/hr?
15 minutes = 0.25 hours
v = d / t
v = 16 km / 0.25 hrs
v = 64 km / hr
300
On a distance time graph.
What goes on the y-axis and on the x-axis?
This graph tells you what?
The y-axis is the distance
The x-axis is the time
This graph tells you the speed of an object.
300
Calculate the resultant force
RF= 15 N to the Left
300
The force acting on the nut os 125 N and the distance of the spanner is 45 cm. What is the motion in Nm?
m = F x s
F = 125N and s = 45cm = 0.45m
m = 125N x 0.45m
m =56.25 Nm
300
What pressure does a 4000N horse exert on the ground if each foot is 10 cm²?
p = F / A
F = 4000 N ; A = 10 cm2
p = 4000N / 10 cm2
p = 400 N/cm2
300
Explain this journey in your own words. (no math needed.)
He walks forward in one direction about 100 metres. He then goes the opposite direction, backwards, about 60 metres and then travels back forward and reaches the bus stop.
400
Which segmant is the fastest? How can you tell?
Calculate the average speed of this segment.
A to B is the fastest.
We know because it is the steepest slope.
The speed = distance / time
d = 200m and t = 10s
v = 200m /10s
v = 20m/s
400
What force does the arrow represent? What would the girl need to do to make the box move forward?
The arrow is friction that goes against the motion of the box. The girl needs to have a force greater than the friction to move the box.
400
Find the Force assuming the example is balanced.
m1 = m2
F x 0.25m = 0.50m x 5N
F = 2.5Nm / 0.25
F = 10N
400
A fast moving car is going 40 km/hr.
The pressure of wind on the car goes up by 2.5 N/m² every 10km/hr faster.
What is the force acting on the wind shield of a car with that is 9 m2 going 40 km/hr?
P = 4 x 2.5 = 10 N/m2
A = 9 m²
P = F / A
F = P x A --> 10 N/m² x 9 m²
F = 90 N
400
A student is measuring the time taken for a ball to be dropped from the 6F of Ying Hai which has a distance of 65m. He recorded this time.
2.35 s, 2.45 s, 2.22 s, 2.51 s, 2.98 s, 2. 25 s
a) What is the anomalous result?
b) Calculate the average speed without the anomalous result.
a) anomoulus is 2.98 s
b) average times =
2.35 + 2. 45 + 2.22 + 2.51 + 2.25 = 11.78 /5
t = 2.356 s
distance = 65 m
v = 65m / 2.356s
v = 27.59m/s
500
A airplane lifts off and continuously increases its speed.
It reaches max speed at 0.5 hours and continues that speed to 1.5 hours.
At 1.5 - 2.0 it slows down because of high winds.
It then goes back to its max speed for the rest of the flight to 3.5 hours.
It prepares to land and slows down from 3.5 to 4 hours and lands to a stop.
Create a distance line graph of this example.
Check all groups
Award as following
+ 100 for correct x and y axis label
+ 100 for accellerated start
+100 for stationary for second
+100 for deaccelarated at 3rd point
+ 100 for increase to max and then decrease to 0 at 4 hours
total awared 500 pts
500
The force that causes a rocket to rise from the ground is called thrust. It is provided by the gases ejected from the rocket engines at the base of the rocket. What must the relationship between thrust and gravity be in order for the rocket to leave the ground?
If thrust were not larger than gravity, what would happen to the rocket?
For the rocket to leave earth and fly up, its thrust would have to be larger than gravity.
If thrust were smaller than gravity, it would fall or not escape earth's gravity.
500
Find out what the reading on the spring balance (newton metre) would say. (Yes, the ruler is horizontal and balanced by the spring.)
0.4m x 200N = 80Nm
F(of spring) = 80Nm / 1.0m
F = 80N
500
A block that is 4 cm x 2 cm x 6 cm is thrown by a child and lands with a force of 200 N.
It lands on the ground. What is the maximum pressure that the block can have on the ground?
(have your answer in N/m²)
smallest area = 4 cm x 2 cm = 8 cm²
area in m² = 8 cm² / 1000 = 0.0008 m²
Force = 200N
max pressure
P = F / A --> 200 N / 0.0008 m²
P = 250,000 N/m²
500
A submarine is travelling 100 m under the sea to see the ocean life. The windows of the submarine have an area of 1.50 m². The force of water every 10 metres is 95,000 N.
How much pressure is acting on the submarine’s window?
distance = 100m
pressure at 100m = 10 x 95,000 = 950,000 N
The window = 1.50 m2
p = F / A
p = 950,000 N / 1.5 m²
p = 633,333.33 N/m²