Topic 1 - Motion, Forces, Newton’s Laws & Stopping Distance Flashcards
Are force and velocity vector or scalar? (1)
Force = vector
Velocity = vector
What’s a vector quantity? (1)
It has direction and size
Calculate the acceleration of a train, at 34seconds and 26m/s. (3)
Acceleration = change in velocity/time (1)
26-14/34 (1)
0.35m/s^2 (1)
What decreases the stopping distance of a car? (1)
Had more passengers
Had worn tires
Needed new breaks
Was travelling more slowly
Was travelling slower (1)
A car travelling at 15m/s comes to rest in a distance of 14m when the brakes are applied.
Calculate the deceleration of the car. (3)
Acceleration = change in velocity/2xdistance (1)
15/2x14 (1)
8.04m/s^2 (1)
Which of these is a vector? (1)
Mass
Force
Energy
Distance
Force
Which of these is a vector? (1)
Energy
Force
Mass
Work
Force
How would the line look in a speed time graph for: (2)
The car is standing still
The car is accelerating
The car is decelerating
The car is travelling at a constant speed
The car is standing still - horizontal line at 0m/s
The car is accelerating - line with a +ve gradient
The car is decelerating - line with a -ve gradient
The car is travelling at a constant speed - horizontal line not at 0m/s
Which of these speeds foul be normal for a person walking? (1)
0.1m/s
1.0m/s
10m/s
100m/s
1.0m/s
A car with a mass of 1800 kg is accelerating at 1.2 m/s2. Calculate the force used to accelerate the car. (2)
Use the equation force = mass × acceleration
1800x1.2 (1)
2200 (1)
A box falls to a hard floor and crumples a little before it comes to rest.
The momentum of the box just before it hits the floor is 8.7 kg m/s.
The box comes to rest 0.35 s after it first hits the floor.
Calculate the magnitude of the force exerted by the floor on the box. (2)
Force = change in momentum/time OR 8.7/0.35 (1)
25N (1)
The gravitational field strength on the Moon = 1.6 N/kg.
The mass of a rock on the Moon is 6.0 kg.
Calculate the weight of this rock on the Moon. (3)
Use the equation weight = mass × gravitational field strength
6 x 1.6 (1)
9.6 (1)
Newtons (1)
A student investigates the effect of a crumple zone on the force exerted during a collision.
The student has one trolley with a spring at the front and another trolley without a spring. After a trolley is released, it accelerates down a slope and bounces off a rigid wall.
The speed of a trolley can be measured just before a collision with the wall and just after a
collision with the wall.
The silver foils are connected to a millisecond timer.
The silver foils make contact with each other during the collision, so the time they are in
contact can be read from the millisecond timer.
Explain how the student could investigate the effect of a crumple zone on the average force
exerted during the collision.
Your explanation should include:
• how to determine the force (you may wish to refer to an equation from
the list of equations at the end of this paper)
• how the effect of crumple zones may be shown in the investigation
• precautions that may be necessary to achieve accurate results.
Determining force:
Use of F=change in momentum/time or F=ma
Mass of trolley needed
And times during impact
Showing effect of crumple zone:
Experiment repeated with & without the spring
Note difference in contact times
Use of spring as crumple zone
With spring, time for contact greater, less impact force
Precautions/controls:
Times repeated & average taken
Careful controls, e.g. same starting position/same angle of slope/release without pushing etc.
A toy car has a mass of 0.10 kg.
The toy car accelerates at 2.0 m/s^2.
Calculate the force producing this acceleration. (3)
Use the equation F = m × a
0.1x2 (1)
0.2 (1)
Newtons (1)
Correct equation relating force, mass & acceleration
Force = mass x acceleration
A cyclist has a mass of 70 kg.
Calculate the force needed to accelerate the cyclist at 2.0 m/s^2.
State the unit. (2)
140 (1)
Newtons (1)
A plane has an upwards force of 8.4kN and a downwards force of 7.5kN. Determine the size and direction of the resultant vertical force on the aeroplane. (2)
0.9 (1)
Up (1)
The mass of an aeroplane is 750 kg.
Calculate the change in GPE of the aeroplane as it descends from 1300m to the ground. (2)
Gravitational field strength (g) = 10 N/kg
750 x 10 x 1300 (1)
9 800 000J (1)
Figure 13 shows 2 objects before and after they collide. Explain how momentum is conserved in the collision. Use Newton’s 3rd law and Newton’s 2nd law in your answer. It can be written as Force=change in momentum/time
(6)
Q-> R Q-> R->
Momentum = mass x velocity
Action & reaction are equal & opposite
Force of R on Q = force of Q on R
Change in momentum of Q/time= change in momentum of R/time
Time of collision same for both
No overall change in moment
R accelerates because of force from Q
Transfer of momentum between Q & R
The Asteroid Belt is part of our Solar System.
Vesta is an asteroid in the Asteroid Belt.
Vesta has an orbital speed of 1.9 × 10^4 m/s.
Vesta travels a distance of 2.2 × 10^12 m when it orbits the Sun once.
Calculate the time taken for Vesta to orbit the Sun once. (2)
Time = 2.2 × 10^12 / 1.9 × 10^4 (1)
1.2 x 10^8 (1)
A car travelling at 15 m/s comes to rest in a distance of 14 m when the brakes are applied.
Calculate the deceleration of the car. (3)
Acceleration = change in speed^2 / 2xtime (1)
15^2/2x14 (1)
8.04 m/s (1)
The force that keeps an object moving in a circular path is known as the… (1)
Centripetal force
The diagram shows a G-machine. Which direction does the centripetal force on the astronaut (A) act? (1)
O—————A
Towards the centre of the circle (o)
Increasing the speed of rotation of a G-machine will …………………………………………
the centripetal force on the astronaut. (1)
Increase
The greater the radius of rotation, the ………………………………….. the centripetal force on the astronaut. (1)
Smaller
The G-machine is rotated by an electric motor.
The following statements explain how the motor creates a turning force. The statements are in the wrong order.
M – The magnetic field interacts with the magnetic field of the permanent magnets.
N – A magnetic field is created around the coil.
O – The power supply applies a potential difference across the coil.
P – This creates a force that makes the coil spin.
Q – A current flows through the coil.
Arrange the statements in the correct order.
O – The power supply applies a potential difference across the coil.
Q – A current flows through the coil.
N – A magnetic field is created around the coil.
M – The magnetic field interacts with the magnetic field of the permanent magnets.
P – This creates a force that makes the coil spin.
An electric motor produces a turning force. Give 2 ways of increasing the turning force.
Increase the current/p.d. (1)
Increase the number of turns of the coil (1)
Increase the area of the coil (1)
Increase the (strength of the permanent) magnetic field (1)
The athlete throws a heavy metal ball attached by a wire to a handle. The hammer thrower swings the hammer round in a circle before letting go. He swings the hammer slowly at first and then faster.
Complete the following sentence. (1)
As the speed of the swing increases, the centripetal force on the hammer ___________.
Increases
Finish the sentence by selecting an option
The centripetal force is provided by the ________
Air resistance
Gravitational force
Tension in the wire
Tension in the wire
A hammer thrower swinging a hammer anticlockwise in a circle. The athlete let’s go of the hammer, which direction does the hammer move? (1)
Person
/ A B/
X D C
C
A skateboarder moving in a circular path.
Another skateboarder has a smaller mass.
Complete the following sentence:
She uses the same part of the ramp at the same speed. The force which allows her to move in a circular path will need to ________. If she goes faster, this resultant force will need to ________.
Decrease
Stay the same
Increase
Decrease
Increase
On their website, the managers of a skateboard park give the following information about some of the ramps where skateboarders move in a circular path.
Name of ramp / Inside radius of the ramp in metres
Bull pit / 6
Dragon’s den / 11
Tiger cage / 8
Witch’s cauldron / 7
A skateboarder uses each ramp at the same speed.
Name & explain the ramp where the resultant force on the skateboarder will need to be the greatest.
Bull pit, because it has the smallest inside radius.
The hammer throw is an athletic event.
The athlete throws a heavy metal ball attached by a wire to a handle. The hammer thrower swings the hammer round in a circle before letting go. He swings the hammer slowly at first and then faster.
Complete the following sentence by choosing an option.
As the speed of the swing increases, the centripetal force on the hammer _________.
decreases
does not change
Increases
Increases
A racing car can accelerate by changing ________.
It’s direction only
It’s speed only
either its direction or its speed
Either it direction or it’s speed
A racing car moves round a circular part of a racetrack.
A force acts on the racing car. The force is towards the centre of the circular part of the racetrack.
Complete the following sentences:
The force is caused by _________. (Electrostatics/friction/gravity)
The force is a _______. (Centripetal force/circular force/perpendicular force)
If another racing car has a greater mass and travels at the same speed around the same racetrack, then the force will need to _______. (Decrease/stay the same/increase)
When the racing car goes faster, the force will need to ________. (Decrease/stay the same/increase)
Friction
Centripetal
Increase
Increase
This is an item from a newspaper:
At last night’s meeting, one local resident said, “The racetrack will be noisy but motor racing leads to safety improvements in all our cars.’’
“We’ll need better brakes. Motor racing encourages speeding and leads to more accidents’’, said another.
Most of the residents were against the plan to build a racetrack.
Do you agree with most of the residents?
(Yes) noisy (1)
It disturbs people living nearby (1)
(Yes) encourages people to drive faster (1)
Which makes road accidents more serious/likely (1)
(No) leads to improvements in safety features (1)
Such as better breaks (1)
(Not sure) noisy (1)
But new tires have a better grip (1)
The drawing shows a set of carriages on a roller coaster. The carriages are moving upwards in a nearly circular path at a constant speed. Complete the following sentences:
The carriages will accelerate because of a change in their ___________. (Direction/mass/speed)
The resultant force which causes the carriages to accelerate is the _______ force. (circular/centripetal/gravity)
The resultant force will need to be greater if the _______. (mass of the passengers is greater/radius of the circle is greater/speed of the carriages is less)
Direction
Centripetal
Mass of passengers is greater
Malik uses a camera to photograph the Moon. Complete the sentences with these words:
(converging, diverging, image, longer, object, real, shorter , virtual)
In a camera a …………….. lens is used to produce an ……………… of an ……………….. on a film. The …………………. is smaller than the ………………… and it is a …………………. distance from the lens.
Image
Object
Image
Object
Shorter
