Recent content by Fetch

Yeah I misconstrued the (net) force part. I figured it out now. I needed the normal force (N) and the x-component of the push (F) to find the net force on the beam. My mistake. Thank you.

Homework Statement A construction worker attempts to lift a uniform beam off the floor and raise it to a vertical position. The beam is 2.26 m long and weighs 397 N. At a certain instant the worker holds the beam momentarily at rest with one end a distance d = 1.21 m above the floor, as shown...

How does one add a FBD? I'm new and haven't learned how to post pictures and such.

Homework Statement A locomotive accelerates a 34-car train along a level track. Every car has a mass of 6.2 × 104 kg and is subject to a frictional force f = 165v, where the speed v is in meters per second and the force f is in Newtons. At the instant when the speed of the train is 31 km/h, the...

The magnitude is 73.33. I used the j component (17.49j) as my magnitude for the -y vector (represented as a positive y vector so I could find the reference angle). Then used the dot product to find the angle that it enclosed. It encloses an angle of like 76 or 75 degrees with the positive...

I got 13.65i - (-17.49)j + 74.08k?

Its something like Vector A dot Vector B = abcosθ right? But wouldn't that only give me an angle with respect to the xy plane and not with respect to the variation due to traveling along the z axis?

Yes that is what I meant. I understand that for an xy plane, but when I do it with respect to the 3d plane I get a little lost. I'm having trouble understanding how to find this angle?

I'm stupid. Its 90. Lol. Hey, while you're at it can you explain part C? It asks for the angle between the -y axis and (A-> x (b-> +3k) The answer is 105, but it looks like I lucked into it, would love to understand what's actually going on. I know that the K vector is going upwards, but...

When I work it out I have [(0)-(0)]i - [(0)-(0)]j + [(-5.83*-7.37)-(4.55*-6.84)]k Which comes out to (0)i + (0)j + (74.0891)k Is the answer not 74.1? O.o

Homework Statement Vectors A & B lie in an xy plane. A has a magnitude 7.4 and an angle 142(deg) with respect to the +x direction. B has components (-6.84i, -7.37j) B) What is the angle between the -y axis and the direction of the Cross product between A and B? Homework Equations Cross...

Homework Statement I'm just rewording the question, because there is one thing in particular I'm after. Given a graph of A, B, & C in Concentration(y) versus time(x), can you determine the balanced chemical equation? Is that possible? I guess if you found the rates and then checked to see...

Homework Statement The second order reaction 2Mn(CO)sub5 → Mnsub2 (CO)sub10 has a rate constant equal to 3.0 *10^9 M^-1s^-1 at 25oC. If the initial concentration for Mn(CO)sub5 is 1.0 * 10^-5 M, how long will it take for 90% of the reactant to disappear? Homework Equations Rate Law =...

Homework Statement Consider: A(aq) + D(l) -> B(aq) + C(aq) Rate Law: k[H+][A] Does the rate increase, decrease, or stay the same, when 500mL of water are added to the solution? Homework Equations The Attempt at a Solution My thought was no. The water doesn't have any effect on the chemical...

I guess I just had it in my mind that to describe the projectile motion I needed to make calculations for strictly vertical (left, right) and horizontal (up, down) motions. The angles came as a result of moving counter clockwise from the positive x-axis. First semester of Physics so I don't...