Physics

[Anonymous No.1771949]

I am frusterated, I need help with Phys.

Using the formula d = vi t + 1/2 at2 where d is isplacement in metres, vi is initial velocity in m/s and a is acceleration in m/s2 .

Given d = 4m , t = 5.7s, a = 9.8 m/s2 find vi

Please show me your work too.

[Anonymous No.1771956]

the answer is:
SAGE !!!

[Anonymous No.1771971]

Two steps:
Rearrange the equation to make vi the subject.

Plug the numbers in.

Now do your homework.

[Adrian !wf/oOO.fjg No.1771992]

<div class="math"> d=v_it+\frac{1}{2}at^2n\Rightarrow 4=5.7v_i+\frac{1}{2}(9.8)(5.7)^2\Rightarrow v_i=\frac{4-\frac{9.8 \times 5.7^2}{2}}{5.7}=?</div>

[Anonymous No.1771996]

>>1771971
d= vi t + 1/2 at^2
d / vi= vi t + 1/2 at^2 / vi
d /vi /d= t + 1/2 at^2 /d
vi= t + 1/2 at^2 /d

Like that? >>1771971

[Anonymous No.1772012]

>>1771996
Its a decent attempt but you have made a little mistake or two, I suggest practising on your rearranging of equations.

In this example you should first seperate the terms with vi in from those which dont, its easy to do by taking 1/2at^2 away from both sides.

Then divide both sides by t to find a formula to calculate vi.

hope it helps, just giving answers doesn't help you at all in the long run.