Question

a crane lifts a pallet of concrete blocks 7 ft from the back of a truck. the truck drives away and the crane lowers the pallet 12 ft. what is the final position of the pallet relative to where it started in the back of the truck? the final position of the pallet is ft relative to where it started in the back of the truck.

Explanation:

Step1: Define upward as positive

Let the upward - movement be positive. The crane lifts the pallet 7 ft, so the first displacement is $+ 7$ ft.

Step2: Define downward as negative

The crane then lowers the pallet 12 ft. Since the movement is downward, the second displacement is $-12$ ft.

Step3: Calculate the net displacement

To find the final position relative to the starting - point, we add the two displacements together. The net displacement $d$ is given by $d=7+( - 12)$.
$d = 7-12=-5$ ft.

Answer:

$- 5$