Question

An object was launched from a place P in constant speed to hit a target. At the 15^th second, it was 1400 m from the target, and at the 18^th second 800 m away. Find time taken to hit the target

Answer 1

Let us take the time T along the x-axis and the Distance D along the y-axis.

Given when time T = 15s, the distance D = 1400 m

The corresponding point is (15, 1400)

Also when time T = 18s, the distance D = 800 m.

The corresponding point is (18, 800)

Time taken to hit the Target:

When the target is reached D = 0

∴ (1) ⇒ T = `(1400 - 0)/200 + 15`

T = `1400/200 + 15`

T = 7 + 15

= 22 seconds

∴ The time taken to hit the target is 22 seconds