Question

An object moving with a speed of 2.25 m/s, is rate given by `"dv"/"dt" = - 1.5 sqrt("v")` where v is the dt instantaneous speed. The time taken by the object, to come to rest, would be ______.

Options

• 1s 

• 2s 

• 4s

• 8s

Answer 1

An object moving with a speed of 2.25 m/s, is rate given by `"dv"/"dt" = - 1.5 sqrt("v")` where v is the dt instantaneous speed. The time taken by the object, to come to rest, would be 2s.

Explanation:

`\int_2.25^0 "dv"/sqrt("v")` = -1.5 `\int_0^"t"` dt

`abs(2sqrt"v")_2.25^ 0` = 1.5 t

t = 2 s