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Find how long does it take to hit the ground from a car off a cliff

  • Thread starter antphany
  • Start date
  • #1
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Homework Statement


A 500kg car drives of a 400m cliff located on the surface of the earth how long does it take to hit the ground

Homework Equations



F=ma
F=mg
d=1/d at^2

The Attempt at a Solution



i first did f=mg to find f
then i did f=ma converted that to find a
then did 1/2 at^2 converted that 2
d x 0.5 / 9.8 then i root it to find t
but i got the wrong answer, the answer is 9 seconds can some one tell me what i did wrong
 
Last edited:

Answers and Replies

  • #2
You're looking for an answer in metres, how far something is, is distance.

So the answer can't be 9 seconds. You already have how long it was in the air.
 
  • #3
NascentOxygen
Staff Emeritus
Science Advisor
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1,072
A 500kg car drives off a cliff at 50km/h how far would it land from the base of the cliff if it was in the air for 10 seconds


Homework Equations



F=ma
F=mg
d=1/d at^2
You are interested in its travel in the horizontal. The car experiences no acceleration horizontally.
 
  • #4
11
0
You're looking for an answer in metres, how far something is, is distance.

So the answer can't be 9 seconds. You already have how long it was in the air.
i been studying all night and its rly late i was combining 2 questions in 1 cuz i am soo tired i fixed the question now lol
 
  • #5
NascentOxygen
Staff Emeritus
Science Advisor
9,244
1,072
A 500kg car drives of a 400m cliff located on the surface of the earth how long does it take to hit the ground
This is an entirely different question, now. Your question has become: how long does it take something to fall 400 m, starting from rest.

What equation will you use for that?
 

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