# [SOLVED] Equations of Motion

#### unstopabl3

This is just something which has been bothering me and want your expertise on it.

Initial Velocity = 0
Acceleration = 1
Distance = 3

Find the time taken to cover that distance.

So generally I would use the second equation of motion to get an answer

t=2.45s

But why don't I get the same answer when I try to solve it in this way...

$$\displaystyle a=\frac{v}{t}$$ and $$\displaystyle v=\frac{d}{t}$$

Thus,

$$\displaystyle a=\frac{d}{t}/t$$

$$\displaystyle a=\frac{d}{t^2}$$

$$\displaystyle 1=\frac{3}{t^2}$$

$$\displaystyle t=1.73s$$

What am I doing wrong? Why don't the answers match?

#### mr fantastic

MHF Hall of Fame
This is just something which has been bothering me and want your expertise on it.

Initial Velocity = 0
Acceleration = 1
Distance = 3

Find the time taken to cover that distance.

So generally I would use the second equation of motion to get an answer

t=2.45s

But why don't I get the same answer when I try to solve it in this way...

$$\displaystyle a=\frac{v}{t}$$ and $$\displaystyle v=\frac{d}{t}$$ Mr F says: These equations give average values.

Thus,

$$\displaystyle a=\frac{d}{t}/t$$

$$\displaystyle a=\frac{d}{t^2}$$

$$\displaystyle 1=\frac{3}{t^2}$$

$$\displaystyle t=1.73s$$

What am I doing wrong? Why don't the answers match?
..

unstopabl3

#### unstopabl3

Oh yes! I completely overlooked that bit!

Thanks