Question

If an object with uniform acceleration (or deceleration) has a speed of `3 m/s` at `t=0` and moves a total of 80 m by `t=4`, what was the object's rate of acceleration?

Answer 1

Using the kinematic formula `D =v_i*t+1/2at^2`,
`D=80m`
`t=4s`
`v_i=3m/s`
`a=?`

#80m = 3m/cancels*4cancels+ 1/2 color(blue)(a) *4^2s#
`80m-12m=8*color(blue)(a`
`72m=8*color(blue)(a`
`a=72/8=9m/s^2`