Forces Flashcards
Velocity is speed in a given
Direction
When two objects interact. They exert ______ and _______ forces on each other.
Equal and opposite
Acceleration (m/s^2) =
Time taken (seconds)
A moving object acted on by a resultant force: In the same direction as the direction of its motion, does what?
Accelerates
Weight (N) =
Weight (N)= mass (kg) x gravitation field strength (M/kg)
The slope of a distance time graph represents
The speed
_____ distance = thinking distance + braking distance
Stopping
Three factors affecting thinking distance
Tiredness, drugs, alcohol, distractions
Speed (m/s)=
Speed (m/s) = distance travelled (m)
—————————-
Time taken (s)
Force=
Force= mass (kg) x acceleration (m/s^2)
A moving object acted on by a resultant force: in the opposite direction as the direction of its motion, does what?
Decelerates
The value of the Earth’s gravitational field strength at its surface is about…
10N/kg
The steeper the slope in a distance time graph, the greater the _______ it represents.
Speed
Braking distance is the distance the vehicle travels
Under the braking force
Thinking distance is the distance travelled by the the vehicle in the time it takes…
For the driver to react
Acceleration is a change of ______ per second
Speed
The unit of force is the ____ (____)
Newton, N
Three factors affecting braking distance:
Poorly maintained brakes and tyre, road and weather conditions
Kinetic energy =
Kinetic energy (J) = mass (kg) x velocity^2 (m/s)^2
—————————————-
2
If the orbital radius for the Earth is 1.5 x 10^11m, what is its orbital speed?
9.42 x10^11m per year or 29,850.18 m/s
What force allows comets and planets to orbit the sun?
Gravitational force
A force of 100N acts on an object for 4 seconds. What is the momentum change of the object?
400 Ns
Vectors have size and _____.
Direction
Moment =
Moment = perpendicular force x distance
What is a comet made from?
Dust and ice
Elastic potential energy can be stored when as an object is _____ or ____.
Stretched or squashed
Change in momentum (kg m/s) =
Change in momentum (kg m/s) = force (N) x time (s)
What is a galaxy?
A collection of billions of stars
An object falling in air resistance reaches a ____ ____
Terminal velocity
A 40kg woman is running at 8m/s. What is her momentum?
320kg m/s
Gravitational field strength, g, is smaller on which astronomical object?
The moon, Pluto, mercury etc
What is true about interaction pairs if forces?
Always equal in size, opposite in direction, act on different ovjects
The kinetic energy of a moving object depends on its ____ and ____
Mass and speed
Orbital speed=
Orbital speed= 2 x pi x r
————-
T
Give three examples of orbiting objects.
Comets, planets, the moon, artificial satellites
Calculate the momentum of a lorry of a mass 5000kg travelling at 2m/s
10000kg m/s
Gravity causes ______ to orbit the sun; moons and _____ to orbit the Earth, and comets to orbit the____.
Planets
Satellites
Sun
Work done (J) =
Work done (J) = force (N) x distance (m)
The more time an impact takes, the _____ force exerted per second.
Less
What is the universe?
A large collection of billions of stars
If car has travelled 3000m in 100 minutes what is its speed in m/min and m/s?
30 m/min
0.5 m/s
A parachutist has a weight of 800N. He is falling at a steady speed. What is the resultant force acting on him?
0 Newtons
An object falling freely accelerates at
10m/s^2 or g
Give three examples of vector quantities in physics
Velocity, time, force, momentum
Gravitational field strength, g, is larger on which planet?
Jupiter, Saturn etc
What is the equation to calculate speed?
Speed =distance/ time
Momentum=
Momentum (kg m/s) = mass (kg) x velocity (m/s)
How does extension vary with applied force for springs?
Proportionally, up to the elastic limit
The _________ system is part of the _______ galaxy, which is a collection of billions of ________. The _______ is a collection of billions of _____.
Solar Milky Way Stars Universe Galaxies
A heavy box is standing on the floor. What is the name of the force holding it up?
Normal contact reaction force
