Question

A body moves in a straight line along, the x-axis. Its distance x (in metre) from the origin is given by x = 8t - 3t². The average speed in the interval t = 0 to t = 1 second is ______.

विकल्प

• 5 ms^-1

• -4 ms^-1

• 6 ms^-1

• zero

Answer 1

A body moves in a straight line along, the x-axis. Its distance x (in metre) from the origin is given by x = 8t - 3t². The average speed in the interval t = 0 to t = 1 second is 5 ms^-1.

Explanation:

Given that x = 8t - 3t²

v = `"dx"/"dt"` = 8 - 6t

when t = 0, v₀ = 8 - 6 × 0 = 8 m/s

when t = 1 v₁ = 8 - 6 × 1 = 2 m/s

v = `("v"_0+"v"_1)/2`

= `(8+2)/2`

= `10/2`

= 5 m/s