You are in browse mode. You must login to use MEMORY

   Log in to start


In English

Created by:
Phillanie Jacobs

5 / 5  (1 ratings)

» To start learning, click login

1 / 25


How do you calculate average speed?

...................................Distance Average Speed = ---------------------- ........................................Time

Practice Known Questions

Stay up to date with your due questions

Complete 5 questions to enable practice


Exam: Test your skills

Test your skills in exam mode

Learn New Questions

Dynamic Modes

SmartIntelligent mix of all modes
CustomUse settings to weight dynamic modes

Manual Mode [BETA]

Select your own question and answer types
Specific modes

Learn with flashcards
Complete the sentence
Listening & SpellingSpelling: Type what you hear
multiple choiceMultiple choice mode
SpeakingAnswer with voice
Speaking & ListeningPractice pronunciation
TypingTyping only mode

Physics - Leaderboard

0 users have completed this course. Be the first!

No users have played this course yet, be the first

Physics - Details



327 questions
How do you calculate average speed?
...................................Distance Average Speed = ---------------------- ........................................Time
Define Displacement
Distance moved by object in a particular direction
How do you calculate velocity?
Change in displacement ------------------------------ Time taken
How do you calculate change in time?
Change in displacement --------------------------- velocity
What is the formula to calculate average speed
...................................DISTANCE Average speed = ---------------------------- .......................................TIME
Acceleration of something indicates what?
Acceleration of something indicates the rate at which its velocity is changing.
Acceleration is defined as?
Rate of change of velocity
What is the formula we use to find average acceleration?
Change in velocity ------------------------ Time taken
Units of acceleration is
M s^-2 Meters per second squared
Explain how using light gates we can measure acceleration Give formula used.
Computer records time of first 'interuption' section of card to pass through light beam of the light gate. Given the length of the interrupt, it can work out the trolley's initial velocity u Repeated for second interrupt to give final velocity v Computer also records time intervals t3-t1 between these two velocity measurements Formula: v-u ----- t3 -t1
Explain how using ticker-timer we can measure acceleration
Tape divided into sections, every 5 dots Time interval between adjacent dots is 0.02 s. Each section represents 0.10s By placing sections of tape side by side, you can picture velocity-time graph
Equations of motion can only be used for:
- Motion in a straight line - Object with constant acceleration
What are the 4 equations of motion
1. v= u + at 2. s=((u+v) / 2 ) x t 3. s= ut + 1/2 at^2 4. v^2 = u^2 + 2as
How do you use equations of motion
1. Write quantities we know, and quantities we want to find 2. Choose equation that links quantities, substitute values 3. Calculate unknown quantities
How to find the acceleration of the velocity-time graph
1. At the time of interest, mark a point on the graph. 2. Draw a tangent to the curve at that point 3. Make a large right-angled triangle, use it to find the gradient
What is known as the acceleration of free fall, and what is the symbol?
Measure the acceleration of a freely falling object on the surface of the earth, we find the value at about 9.81 m s^-2, and it is given by symbol g
Explain how we measure g using an electronic timer in the laboratory. (3) What does this tell us. (1) What equation of motion must we use to find g (1) What are sources of uncertainty (4)
A steel ball-bearing is held by an electromagnet When the current is switched off, ball begins to fall, and electronic timer starts. Ball falls through trap door and breaks circuit, stopping timer Tells us time taken for ball to fall from rest trough distance h between bottom of baal and trapdoor H=1/2gt^2 Electromagnet may retain some magnetism when it is switched off, can slow balls fall Time t recorded by timer may be longer than if ball were to fall completely freely - From h=1/2gt^2 if t is to great, experimental value of g will be too small Measuring height h is awkward and value of h will be given ±1 mm at best
Explain how we measure g using ticker-timer in the laboratory Where does the main problem arise
A weight falls As it falls, it pulls a tape through ticker timer Spacing of dots on tape increases steadily, showing weight is accelerating Analyse tape to find acceleration Main problem arises from friction between tape and ticker-timer. It slows down the fall of the weight so its acceleration is less than g. Friction is less of a problem if the weight is larger, thus falling more freely
Explain how we measure g using a light gate in the laboratory What is this methods advantage over measuring g using an electronic timer.
Weight can be attached to card 'interrupt'. Card is designed to break light beam twice as weight falls. Computer can calculate velocity of the weight twice as it falls, and hence finds its acceleration Weight can be dropped from different heights above light gate. Allows you to find whether acceleration is the same at different points in its fall.
To find the components of any vector in a particular direction, we use following strategy:
1. Find angle 0 between vector and direction of interest 2. Multiply vectors by cosine of the angle 0
One of the characteristics that make up a 'Newton's third law pair is forces of the same type. Give 5 examples of this?
1. Gravitational forces 2. Electrical forces 3. Contact forces 4. Tension forces 5. Magnetic forces
One of the characteristics that make up a 'Newton's third law pair is forces of the same type. Give 5 examples of this?
1. Gravitational forces 2. Electrical forces 3. Contact forces 4. Tension forces 5. Magnetic forces
What is the symbol and unit for mass
Symbol = m Unit = kg (kilograms)
What is the symbol and unit for acceleration
Symbol = a Unit = m s^-2 (meters per second squared)
What is Newton's second law of motion?
For a body of constant mass, its acceleration is directly proportional to the resultant force applied to it
The equation a = F / m relates acceleration, resultant force and mass. What does it show in particular?
It shows that the bigger the force, the greater the acceleration it produces
What is inertia?
The mass of an object is a measure of its inertia, or its ability to resist any change in its motion Greater the mass, smaller the acceleration that results
Define the centre of gravity of an object
Centre of gravity of an object is defined as the point where its entire weight appears to act.
What is the symbol, unit and base unit of mass
Symbol = m Unit = kg In terms of base units = kg
What is the symbol, unit and base unit of weight?
Symbol = mg Unit = N In terms of base units = kg m s^-2
In the 17th century Galileo came to 2 conclusions about the natural motion of objects, what are they
1. An object at rest will stay at rest, unless a force causes it to start moving 2. A moving object will continue to move at a steady speed in a straight line, unless a force acts on it.
What is uniform motion?
Natural state of motion of an object
What is Newton's first law of motion?
If no resultant force acts on an object it will not accelerate. The object will either remain stationary or it will continue to travel at a constant velocity.
What is known as terminal velocity? And what is it approximately ?
Maximum velocity 120 miles per hour (about m s^-1)
What is contact forces?
When two objects touch each other, they exert a force on the other
What is Newton's third law of motion
When 2 objects interact, each exert a force on the other, forces are equal and opposite to each other
What are the 4 characteristics that 2 forces have that make up Newton's third law pair
1. Act on different objects 2. Equal in magnitude 3. Opposite in direction 4. Forces of the same type
One of the characteristics that make up a 'Newton's third law pair is forces of the same type. Give 5 examples of this?
1. Gravitational forces 2. Electrical forces 3. Contact forces 4. Tension forces 5. Magnetic forces
What are 6 examples of base units?
-meter -kilogram - Second - Ampere - Kelvin -Mole
What is the base unit and the symbol for length?
Symbol = x,l,s and so on Base unit = m (meter)
What is the base unit and symbol for mass?
Base unit = kg (kilograms) Symbol = m
What is the base unit and symbol for time
Base unit = s (second) Symbol = t
Vectors have both ?
Magnitude and direction
When you draw a scale drawing you should:
1. State the scale used 2. Draw large diagram to reduce the uncertainty
What are the forces that are acting on a trolley on a ramp ?
1. Wight of the trolley (acts vertically downwards ) 2. Contact force of a ramp - acts at right angles to ramp
Define centre of gravity?
The point where all the weight of the object may be considered to act
Forces can have turning effect, what does this mean?
They can make an object turn around
Moments of a force depends on what 2 quantities?
1. Magnitude of the force 2. Perpendicular distance of a force from a pivot
What is the formula for calculating moment of a force?
Moment of a force = force x perpendicular distance
What are the 2 methods to calculate the moment of the force {1(5)} {2(4)}
1 Draw a perpendicular line from the pivot to the line of a force Find distance x`2 Calculate moment of force = F`2 x x`2 From the right angle triangle we can see that : x`2 = d sin θ Moment of force = F`2 x d sin θ = F`2 d sin θ 2 Calculate component of F`2 that is at 90° to the lever F`2 sin θ x d Moment of a force = F`2 d sinθ
We can use the moment of a force to solve two sorts of problems?
1. Check whether an object will remain balanced or state to rotate 2. Calculate an unknown force or distance if we know that an object is balanced
What does the principle of moments state?
The principle of moments states that, for any object that is in equilibrium, the sum of the clockwise moments about any point provided by the forces acting on the objects equals the sum of the anticlockwise moments about the same point
A couple has a turning effect, but does not cause an object to accelerate. To form a couple, the two forces must be:...(3)
1. Equal in magnitude 2. Parallel but opposite in direction 3. Separate by distance d
What is known as torque
The turning effect or moment of a couple is known as its torque
The torque of a couple is known defined as follows:
Torque of a couple = one of the forces x perpendicular distance between the forces