Question

a body is thrown vertically upward with velocity u the distance travelled by it in the 7th and 8th second are equal the displacement in 8th seconds is equal to​

Answer 1

Answer:

Displacement in 8th Sec = 0

Explanation:

Distance Traveled in 7 sec

S = ut + (1/2)at²

S₇ = 7V - 5(7)²

S₇ = 7V - 245

S₈ = 8V - 5(8)² = 8V - 320

7V - 245 = 8V - 320

=> V = 75

Time to reach Peak = (75 - 0)/10 = 7.5  s

Displacement in 8 sec

Distance from 7 to 7.5 Sec  -  Distance from 7.5 to 8 Sec

Distance in 7 Sec = 7*75 - 245 = 280

Distance in 7.5Sec = 7.5*75 - 5(7.5)² = 281.25

Distnace in 8 sec = 8*75 - 320 = 280

Displacement in 8th Sec = (281.25 - 280) - (281.25 - 280)

= 1.25 - 1.25

= 0

Displacement in 8th Sec = 0