Question

A pyrotechnician plans for two fireworks to explode together at the same height in the air. They travel at speeds shown below. Firework B is launched 0.25 s before Firework A. How many seconds after Firework B launches will both fireworks explode? Firework A 240 ft/s Firework B 200 ft/s​

Answer 1

Answer: 1.50 seconds

Explanation:

Let x = Time taken by Firework A to explode( in seconds ).

Time taken by Firework B = x+ 0.25 seconds

Distance covered = Time × Speed

Distance covered by Firework A = 240 x

Distance covered by Firework B = 200 (x+0.25) = 200x+50

When both at same height , then

240x = 200x+50

⇒ 240x- 200x =50

⇒40x =50

⇒ x = 1.25

Total time = x+ 0.25 = 0.25+ 1.25 = 1.50 seconds

Hence. after Firework B launches it will take 1.50 seconds to launch.