projectile shot upward at 75m/s from a height of 10m off the grand. how long will it take for the projectile to be at ground level?
What equation do I need to solve this problem?

Question

projectile shot upward at 75m/s from a height of 10m off the grand. how long will it take for the projectile to be at ground level?
What equation do I need to solve this problem?

badhi · Answer

try $$S = ut + \frac 1 2 at^2$$

cheska_p · Answer

@BAdhi I get 10m=75m/s(t)+4.9(t)^2 
I'm confused on how to solve for 't'

badhi · Answer

in here the s and u are vectors.. and as convention they are positive upwards. According to the given information since the object is already place 10m higher, to reach the ground level the object has to go 10m downwardes thus S= -10m

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