- #1
RuthlessTB
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While I was studying I downloaded and printed a previous old test which already answered
I tried to re-solve the questions by myself but there is one question made me confused as I get a result mentioned in the options but the marked answer is different.
I am talking about question 3 in the following picture
Vo= 0 m/s
V= 20 m/s
Xo= 0 m
X= 800 m
t= 25 s
a= ?
1) X = Xo + Vo t + 0.5 a t^2
2) V^2 = Vo^2 + 2 a (X-Xo)
I used the first equation
X = Xo + Vo t + 0.5 a t^2
solution will be
800 = 0 + 0 (25) + 0.5 a (25)^2
800 = a 312.5
-a 312.5 = 800
-a = 800/312.5 = 2.56
then I took the square root of 2.56 and I got 1.6 m/s^2
So -a = -1.6 m/s^2
Is that right or no?
I tried to re-solve the questions by myself but there is one question made me confused as I get a result mentioned in the options but the marked answer is different.
I am talking about question 3 in the following picture
Homework Statement
Vo= 0 m/s
V= 20 m/s
Xo= 0 m
X= 800 m
t= 25 s
a= ?
Homework Equations
1) X = Xo + Vo t + 0.5 a t^2
2) V^2 = Vo^2 + 2 a (X-Xo)
The Attempt at a Solution
I used the first equation
X = Xo + Vo t + 0.5 a t^2
solution will be
800 = 0 + 0 (25) + 0.5 a (25)^2
800 = a 312.5
-a 312.5 = 800
-a = 800/312.5 = 2.56
then I took the square root of 2.56 and I got 1.6 m/s^2
So -a = -1.6 m/s^2
Is that right or no?