- (a) Define the NOR Boolean operator. [1]
A car has features that monitor its speed, direction and distance from the car in front. This is shown in Figure 1.
rules to control car motion (table of inputs A, B, C)
(b) Construct a logic diagram with inputs A, B, and C and output Z to represent the following scenario:
Output Z equals 1 when:
- the car is travelling forward AND it is less than 20 metres from the vehicle in front.
OR - the car speed is more than 130 km per hour.
In all other conditions, output Z equals 0. [4]
An additional row (input D) is to be added to assist when the car is in reverse or stationary. Input D checks if there are obstructions less than 3 metres from the rear of the car.
(c) State the rules that need to be added to Figure 1 to test this condition. [2]
Information similar to that presented in Figure 1 could be used to construct decisions and conditions in program design (see Figure 2).
identifiers for car motion rules (table of F, S, T)
(d) Determine the value of the following expression given that the input values for F, S and T are:
F = 40
S = 115
T = true
F >= 25 AND S >= 5 AND S <= 130 AND T = true
You must show your working. [2]