Chapter 5 Acceleration, Using Gears, Braking And Steering

Question 1

When is a vehicle most stable?

Answer 1

A moving vehicle is most stable when its weight is evenly distributed, the engine is just pulling without increasing road speed, and it’s travelling in a straight line.

Question 2

The patch of tyre in contact with the road on a average car is?

Answer 2

Size of a hand

Question 3

Explain the use of the accelerator?

Answer 3

Depress the accelerator:
- to increase road speed
- to maintain road speed: for example when cornering or going up hill
Release the accelerator:
- to reduce engine speed and slow the vehicle down.

Question 4

What benefit is there lowering gear?

Answer 4

Changing to a lower gear reduced the loaf and allows the engine to speed up and move the vehicle faster

Question 5

What’s a retarder?

Answer 5

Heavy vehicles, including larger emergency vehicles are fitted with retailers. These devices produce additional engine braking to help slow the vehicle

Question 6

Explain vehicle balance when decelerating?

Answer 6

The rear tyres lose grip, the front tyres gain grip

Question 7

Explain vehicle balance when accelerating?

Answer 7

The rear tyres gain grip, the front tyres lose grip

Question 8

Explain best practice for acceleration?

Answer 8

Use accurate and smooth movements to release or depress the accelerator. Remember ease and squeeze

Question 9

What is acceleration sense?

Answer 9

Acceleration sense is the ability to vary vehicle speed in response to changing road or traffic conditions by accurate us of the accelerator, so that you use the brakes less or not at all.

• uses less fuel
• causes less wear on the tyres
• reduces emissions

Question 10

Explain acceleration on bends?

Answer 10

Use the accelerator to maintain a constant speed round a bend. A constant speed keeps your weight evenly distributed front and rear, and ensures maximum tyre grip.

Question 11

How to counter under steering?

Answer 11

Reduce the amount of steering, start to accelerate but do this gently and smoothly so that you maintain tyre grip. As steering reduces, the tyre grip trade off allows more grip for acceleration but be aware of accelerating too early. The appropriate point depends on how far you can see and the conditions on the road surface.

Question 12

Your vehicle can only increase speed if the engine can deliver the power, and it can only do this effectively if you’re in the correct gear. Aim to:

Answer 12

• be in the correct gear for every road speed and traffic situation
• make all gear changes smoothly
• engage a chose gear without going through an intermediate gear first
• know the approximate maximum road speed for each gear
• know the most efficient point at which to change up

Question 13

The main effect of the gears is to transform engine revs into useable power. Explain?

Answer 13

• in a low gear, the engine is able to Rev more freely, which allows the vehicle to accelerate rapidly and to climb slopes
• in a higher gear, lower revs deliver more speed but less ability to accelerate or to climb slopes
• intermediate gears allow progress from one extreme to the other
• a lower gear also restrains the vehicles speed when descending a slope.

Question 14

Explain first gear?

Answer 14

Produces plenty of road wheel turning power but not much speed

Question 15

Explain intermediate gears?

Answer 15

Produce varying combinations of wheel turning power and speed

Question 16

Explain top gear?

Answer 16

Produces plenty of speed but not much wheel turning power

Question 17

Changing to a lower gear, helps when?

Answer 17

• travelling at low speeds
• going up hill
• going downhill, because engine compression slows the descent
• approaching a hazard
• on slippery roads, where you should ease off the accelerator to lose speed gently, so as to avoid skidding

Question 18

What are high gears good for?

Answer 18

• cruising at speed
• certain slippery conditions where lower gears may cause wheel spin

Question 19

Should you change gear whilst cornering?

Answer 19

No- it destabilises the vehicle and required you to take one hand off the steering wheel.

Question 20

Explain engine braking?

Answer 20

When you release the accelerator, the engine slows and through engine compression exerts a slowing force on the wheels. This causes the engine to act as a brake, reducing the road speed smoothly and gradually with little wear to the vehicle.

Question 21

What is normal braking (tapered braking)?

Answer 21

Braking should normally be progressive and increased steadily.

Question 22

What is the safe stopping distance rule?

Answer 22

Always drive so that you can stop safely within the distance you can see to be clear on your own side of the road

Question 23

What is the stopping distance formula?

Answer 23

Thinking distance + braking distance = stopping distance

Question 24

What is thinking distance?

Answer 24

Thinking distance is the distance travelled in the time between first observing the need for action and acting. This is why attitude, observation, anticipation and information processing abilities are vital.

Question 25

Actual thinking distance varies according to:

Answer 25

• the speed of the vehicle
• your physical and mental condition
• your attentiveness
• whether or not you’re expecting something to happen

Question 26

Braking distance depends on:

Answer 26

• the vehicles capability, size and weight
• the gradient of the road and the condition of the road surface- slippery surfaces greatly increase braking distance

Question 27

What is the safe stopping distance rule you should apply?

Answer 27

The two second rule

Question 28

What does ABS do?

Answer 28

The ABS repeatedly releases the brakes just before the wheels lock up and reapplies them in a pulsing action, so that they never fully lock. ABS only works if you apply firm pressure to the brake pedal.

Question 29

Explain emergency brake assist (EBA)?

Answer 29

EBA increases braking pressure in an emergency situation. If you apply the brake with speed and force, EBA will activate and fully apply the brakes until the ABS takes over to prevent the wheels locking up.

Question 30

What is the steering technique recommended?

Answer 30

Pull push method