Help
Options
Didn't know it?
click below
click below
Knew it?
click below
click below
Don't Know
Remaining cards (0)
Know
retry
shuffle
restart
0:00
Embed Code - If you would like this activity on your web page, copy the script below and paste it into your web page.
Normal Size Small Size show me how
Normal Size Small Size show me how
Physics Motion
Physics Autumn Y12
| Question | Answer |
|---|---|
| Is time a scalar or vector? | Scalar |
| Is p.d. a scalar or vector? | Scalar |
| Is volume a scalar or vector? | Scalar = it is a property of an object |
| Is area a scalar or vector? | Vector - depends on which direction it is pointing |
| How to combine vectors | Tip to tail. Order doesn't matter. Then do cosine rule |
| IMPORTANT: Resolving vectors | Vectors can be split into 2 perpendicular components of any orientation. A component is always equal to the magnitude x sin or cos theta. All components are equal to or smaller than original vector |
| How to resolve a vector | If trying to work out the Fx of F (the amount F moves in the x direction), put F and Fx on the sketch and work out if they are S = O/H or C = A/H (H is always F, so it depends on if Fx is opposite or adjacent) |
| A plumb bob has a weight of 1.0N . It is swinging on the end of a piece of string, and at one particular instant, the string is inclined at 28∘ to the vertical. What is the component of the weight perpendicular to the line of the string? 2sf | 0.47 |
| Mass on slope question with resolving vectors equation | Objects mass = m. mg straight down. Force parallel to slope is perpendicular to component down perpendicular to slope. Work out angle between mg and this component as mgcos(theta). So component in direction of slope is ALWAYS mg sin(theta). |
| Mass on slope question with resolving vectors if stationary or going upwards | Forces going up slope must equal mgsin(theta) If going up, a force (m x a) is acting as well, so (e.g. Tension) = mgsin(theta) + ma |
| Tension is constant throughout a string | Trust |
| How to resolve mg on a dangling weight | Resolve upwards (upwards pointing arrow is the symbol for this) |
| Component forces | Always smaller than the main force. perpendicular If angle between resultant and component, use cos (turn away from sin). When one component force cos(angle) x MAIN, other is the same but sin. (must be the main one. To find main one instead, rearrange) |
| Work done | Must be parallel. Work done is only for the component of the force in parallel with the displacement, hence equation on sheet: E = Fd x cos(theta) Same with moments (perpendicular) |
| To show gradient | Say: y = mx Rearrange thing into this form So, |
| Average velocity = | Resultant displacement/total time taken |
| What to say when analyzing displacement time graph | Constant positive/negative velocity. Moving forwards/backwards. Positive/negative displacement But decelerating Stationary (v = 0) Give data for evidence |
| For velocity or displacement time graphs | If line goes down until hitting the x axis, v >= 0. Remember the equals |
| Explain why the velocity of the car changes although speed constant | Mention 'vector' |
| Using a labelled vector triangle, calculate magitude of change in velocity of the car as it travels at 25 m/s around right corner from A to B | Change = final - initial Change + initial = final 'Initial' here will be the vector at A, so the resultant vector will be B A and B perpendicular from the same point (not tail to tip), connected by 'change in v'. The 'path' would be A + change in v |
| Explain why values for average speed and average velocity are different | Displacement =/= distance Displacement in straight line |
| Projectile motion | Consider horizontal and vertical component separately, then use SUVAT |
| Arrow fired horizontally at x speed from y tall. Calculate velocity when hits the ground | Find horiz velocity (the same as start). Find vertical velocity (SUVAT). Pythagoras for actual velocity |
| Describe motion of ball up ramp | Up for x seconds with constant negative acceleration. Momentarily stops. Rolls back. |
| Car travelling on circular track. Explain why displacement looks (like a parabola) | Displacement is direct distance from A, so symmetrical about x. Comes back to 0 as it completes the circle. |
| When explaining how to find acceleration from curve on vt graph | Draw tangent and calculate gradient *because a = v/t* |
| What is a newton? | The amount of force to accelerate 1kg by 1ms^-2 |
| Acceleration units | Check to make sure it's always ^-2 |
| Why W = mg | Only force acting is weight and has g acceleration f = ma |
| Mass defining | Physical property based on the amount of matter of an object |
| Resultant force effect | Makes an object accelerate in the direction of the net force |
| 8g pellet at 420ms^-1 hits crate, penetrating 98mm. Calculate average magnitude of force on pellet | Needs SUVAT Remember to make mm into m |
| Constant a from rest. Travels 12m in second second. How far in fourth? | Graph. Average time of second one is 1.5. Average velocity for that second is 12m, which is at 1.5s. In 1.5s reached 12m/s so a = 8. SUVAT. |
| Main issue with Motions test | Shape of graphs of different SUVAT variables e.g. 'which graph not straight line' 'graph of __ against __' |
| What is the velocity of the max height of a bounce? | 0 |
| When working out total horizontal distance travelled with projectile motion | Don't need complicated half curve time. Just have displacement be zero. |
| Car stopping distances | Point of seeing to stopping. Thinking + braking distance Braking distance proportional to u^2 (because all KE needs dissipating and KE = 1/2mv^2 Thinking - distract, tired, drugs Braking - road surface and car condition e.g. brakes, tires, mass |
Created by:
Pyrogearos2