Ack! I thought i knew this!(adsbygoogle = window.adsbygoogle || []).push({});

"A car manufacturer test crash resistance by driving test vehicles off a horiztontal platform so that they fall to a concrete surface below.If this car is driven off at 20m/s and the platform is 15m above the ground calculate the impact angle and speed"

Im not to fussed about the impact angle just yet, i tried to work the speed out...

u = 0

a = 9.8

s (displacement) = 15

v = ?

t = ?

For this i need to use the equation: [tex]v^2 = u^2 + 2as[/tex]

[tex]v^2 = 2 \times 9.8 \times 15[/tex]

[tex]v^2 =294[/tex]

[tex]v = 17.15 m/s[/tex]

But the answer in the book is different, it says 26.3 m/s

Im most probably making an incredibly stupid mistake, please spot it!

thanks,

Regards,

Mo

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# Homework Help: Projectile Problem

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