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1. ### How do I derive this equation? HELP

How do I derive this equation?!? HELP! I started with the equation: y=yinitial + (vinitialsintheta)t -1/2gt^2 I plugged in t=x/(vinitialcostheta) to get: y=yinitial + x (tantheta) - [(gx^2)/(2(vinitial^2)(cos^2theta))] Using derivatives, how do I get from this equation: y=yinitial...
2. ### Elastic Glancing Collision-HELP

I used this equation: 1/2mv_1i^2 = 1/2mv_1f^2 + 1/2mv_2f^2 (the 1i, 1f, and 2f are subscripts indicating which velocities) When I plugged in the numbers from the problem, I got that the final velocity for the yellow ball is 0.801m/s. I then used the following equation...
3. ### Elastic Glancing Collision-HELP

Elastic Glancing Collision-HELP! A white ball, mass of 1 kg has a speed of 1.68 m/s and a yellow ball, mass of 2kg, is at rest prior to an elastic glancing collision. After the collision the white ball has a speed of 1.24 m/s. To the nearest tenth of a degree, measured counterclockwise from...
4. ### Momentum- HELP

Momentum- HELP! A 40kg child stands at one end of a 70kg boat that is 4m in length. The boat is initially 3m from the pier. The child notices a turtle on a rock at the far end of the boat and proceeds to walk to that end to catch the turtle. Neglecting friction between the boat and the water...
5. ### Gaussian Elimination

Solve the following system of equations using Gaussian elimination: 3w+10x-2y+3z=55 w+12x-11y-z= 69 -3w-6x-5y-10z=-47 -3w+9x+5y+4z=-1 Here's what I did so far: swap R1 and R2 (row 1 and row 2) -3R1+R2 (multiply row 1 by -3 and add row 2 to that product) 3R1+R3 3R1+R4 Now, after...
6. ### Frictionless physics problem

I still don't know what equation to use to relate tension to the other values...
7. ### Frictionless physics problem

1. A 1.5 kg rock is being twirled in a circle on a frictionless surface using a horizontal rope. The radius of the circle is 2.00m and the rope makes 100 revolutions in 1.00 minutes. What is the tension in the rope? This problem has totally confused me. I don't even know what equation to...
8. ### Newton's laws problems HELP !

It's too hard to show the work, and, as I said, some of the problems I was completely stuck on. Anyway, it's too late now. I don't need it anymore. I do understand where you're coming from, though. Thanks anyway.
9. ### Newton's laws problems HELP !

Newton's laws problems HELP! These are the problems that I either tried and thought I got the wrong answer :eek: or got half-way through and got completely stuck on. :bugeye: Any help would be greatly appreciated.:redface: Thanks! :wink: 1. A 43.8-kg sign is suspended by two ropes with...