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Topic: **Being solving this problem we****Question:**
On a test it said
"An object was shot from the ground at 35 degrees and landed 600 meters away. What was its initial velocity?"
I answered about 108.
My friend answered about 48.
Can you tell me if either of us were right, and basically what you would do to solve it?
I used Final Velocity squared=Initial Velocity squared +2*Gravity*Distance
Was this the right formula?

April 25, 2019 / By Chance

Hello Gina No, you can tell by just looking, your answer should be much smaller than the weight of the trunk. Normal Force (N) = W * cos 26 = 82 N * cos 26 N = 73.7 N Force of Friction = u * N = 0.20 * 73.7 N Force of Friction = 14.74 N Notice that the speed of the trunk (or acceleration) does not affect the friction force, only the weight, angle and coefficient. Good Luck

This is a messed up problem. The trunk is being pulled down teh slope by a component of the gravity force. That is 82 . sin 26 N It is being opposed by the frictional force F So the accelerating force is 82.sin26 – F which must = m . a You are told "a" and "m" must be 82 / g So F = (82. sin26) – ( (82 / g) . 0.5 ) = 31.77 = 32 N But - as shown by Mugwump the frictional force can only be about 14 N, if the coefficient of friction is correct. In other words something is wrong with the way the problem has been set. This motion is not possible with these numbers. But if you have understood why it's messed up.... that means you will find the good problems dead easy. Good luck ;-)

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