PLEASE HELP SOON I DONT UNDERSTAND THIS QUIZ

Chuck drops a rock from a height of 70 m. How long will it take the rock to hit the ground?

Use the formula h(t)=−4.9t^2+v0t+h0, where v0 is the initial velocity and h0 is the initial height.

Round to the nearest tenth of a second. Enter your numeric answer.

PLEASE HELP SOON I DONT UNDERSTAND THIS QUIZ Chuck drops a rock from a height of 70 m How long will it take the rock to hit the ground Use the formula ht49t2v0 class=
PLEASE HELP SOON I DONT UNDERSTAND THIS QUIZ Chuck drops a rock from a height of 70 m How long will it take the rock to hit the ground Use the formula ht49t2v0 class=
PLEASE HELP SOON I DONT UNDERSTAND THIS QUIZ Chuck drops a rock from a height of 70 m How long will it take the rock to hit the ground Use the formula ht49t2v0 class=
PLEASE HELP SOON I DONT UNDERSTAND THIS QUIZ Chuck drops a rock from a height of 70 m How long will it take the rock to hit the ground Use the formula ht49t2v0 class=
PLEASE HELP SOON I DONT UNDERSTAND THIS QUIZ Chuck drops a rock from a height of 70 m How long will it take the rock to hit the ground Use the formula ht49t2v0 class=

Respuesta :

1. h₀ = 70  

v₀ = 0 since the rock is dropped it has no initial velocity  

when the rock hits the ground the height = 0  

plug into the formula  

0 = -4.9t² + 0(t) + 70  

0 = -4.9t² + 70  

Add 4.9t² to both sides  

4.9t² = 70  

Divide both sides by 4.9  

t² = 14.2857142857  

Take the square root of both sides  

t = 3.7796447301  

t ≈ 3.8 seconds

I am not doing the rest I only did one just to help you understand a bit more