Explain what the hazard detection unit is doing during the 5th cycle of execution. Which registers are being compared? List all pairs of registers that are compared during the 5th cycle for the hazard detection unit. (You need to determine which instruction's values are in the IF/ID and which instruction's values are in the ID/EX register during the 5th cycle. Then check the conditions for the hazard detection.)

The registers that are compared are instructions 3 and 4

Explanation:

From the question given,

Recall that we need to explain what the hazard detection unit is doing  during the 5th cycle of execution and which registers are being compared.

Now,

The instructions on the 5th cycle, at the stage ID/EX and IF/ID:

The instruction values are in ID/EX : sub $t2, $t3, $t6 (instruction 3)

The instruction values are in IF/ID: sub $t3, $t1 $t5 (instruction 4)

The register $t3 is compared in the instructions 3 and 4

The hazard detection unit between instruction 4 and 5t o be compared, it need to find out the values of $t1

only #2 represents an object at rest on a table.

in #1, there is no normal force due to the table; the object is accelerating downward.

in #3, the vertical forces are not balanced; the object is accelerating downward.

in #4, neither the vertical nor the horizontal forces are balanced. the object is accelerating upwards and to the right.