Hello, I had a question for physics, and I tried it out, however, I got the wrong answer.

Question

The Question:If a rock takes 0.750s to hit the ground after being thrown down from a height of 4.80m, determine the rock's initial velocity.

My Work : The formula- d=vi*t+1/2*a*t^2
The isolated formula-(2*d)/(t*a)=vi

So it would be (2*4.80m)/(0.750s*9.81m/s^2)=vi
1.30m/s=vi

The correct answer is 2.72m/s[down]/

You you please show me where I went wrong? Thank you!

Answer 1

Heres your answer by the Verified user.

your formula is incorrect the right formula is as defined

[Formula used]

d=(ViT)+(1/2at^2)

vi=(0.75/4.8)+(1/2*9.8*0.75^2)

Vi = (2.9)Answer

Answer 2

Heres your answer by the Verified user.

your formula is incorrect the right formula is as defined

[Formula used]

d=(ViT)+(1/2at^2)

vi=(0.75/4.8)+(1/2*9.8*0.75^2)

Vi = (2.9)Answer

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