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few questions about newton's 2nd law that i'm stuck on =[

An 80kg skier has a force 200N exerted on him down a slope.
Calculate his aceleration down the slope.
Is the slope less than or more than 45(degrees)? explain your answer.

80 x 9.81 = 784.8N

I'm not sure which one of these is right...

200N = 80 x a
a = 2.5 m/s^2

or

200 - 784.8/cos (theta) = 80

a

a=16000-62784/cos (theta)

I'm not sure how to work out the second part.

Thanks!!
any help will be greatly appreciated!
and +rep to the person who offers the most thorough and conclusive answer!

Reply 1

O.o mY SaRcAsM

200N = 80 x a
a = 2.5 m/s^2

thats right

well it says 'explain' so no calculation generally needed...so my guess would be more but i dont have a proper answer to that....just cant imagine someone whose 80kgs going down a slope at 2.5ms-1 at an angle less than 45
sorry thts all i can do atm

Reply 2

div curl F = 0

Spongebob*No*Pants

200 - 784.8/cos (theta) = 80

a

a=16000-62784/cos (theta)

I'm not sure how to work out the second part.

Thanks!!
any help will be greatly appreciated!
and +rep to the person who offers the most thorough and conclusive answer!