| What is terminal velocity? | The maximum speed of an object reached when the forces moving the object are balanced by its frictional forces. The objects move at steady speed in a constant direction with a resultant force of 0. |
| What is inertia? | The tendancy of an object to continue in its current state of motion(rest or uniform in motion) |
| What does it mean if the resultant force is 0? | If resultant force is 0 then a stationary object remains stationary and a moving object remains moving. The forces are balanced |
| What is the required practical to investigate the effect of varying force on the acceleration of an object at a constant mass? | 1)Place an air track on a bench with a bench pulley at one end and two light gates above the track. Cut an interrupt card to a length (eg 10 cm) and attach it to an air track glider.
2)Connect the glider to a hanging mass by a string that is the length of the air track passing over the bench pulley. Make sure the air track is level & the card will pass through both gates before the mass strikes the floor.
3)Set the data logging software to calculate acceleration.
4)Add 5 × 20 g slotted masses (0.98 N of force) to the end of the string.
5)Release the glider, then record the weight and acceleration.
6)Repeat steps 4 and 5 two more times, and calculate a mean value for the acceleration.
7)Repeat steps 4 to 6, removing one of the slotted masses each time ,giving forces of 0.78 N, 0.59 N, 0.39 N and 0.20 N. |
| What 2 factors effect braking distance? | 1)Poor road and weather conditions
2)Poor vehicle condition, worn brakes/tires |
| How can you estimate the total stopping distance of a car using its speed? | speed=20mp
thinking distance=6m
braking distance=6m
total=12
AS SPEED DOUBLES, THINKING DISTANCE DOUBLES, BRAKING DISTANCE TIMES 4 SO:
speed=40mp
thinking distance=12m
braking distance=24m
total=36 |
| What are the 3 stages of falling? | 1)Accelerating downwards due to gravity
2)Frictional forces such as air resistance increase
3)The object reaches terminal velocity, weight of object balanced due to frictional forces, resultant force is 0 |
| What is Newtons first law of motion? | An object remains in the same state of motion unless a resultant force is acting on it. |
| What is Newtons second law of motion? | Force(N)=mass(Kg)aceleration(m/s) |
| Whats inertial mass? | A mesure of how difficult it is to change the velocity of an object. Found using force over acceleration |
| What is Newtons third law? | Whenever two objects ineract they exert equal and opposite forces. |
| What is stopping distance? | stopping distance=thinking distance+braking distance |
| What 4 factors effect thinking distance? | 1)tiredness
2)drugs
3)alchahol
4)distractions |
