Tuesday

July 29, 2014

July 29, 2014

Posted by **Stephanie** on Friday, April 22, 2011 at 9:35am.

I have Fx=T1(x) + T2(x)= 0 to calc the first tension, and Fy= T1(y) + T2(y) + w = 0 for the second tension.

To get T1(x)and T2(x) I took cosine of angle 20 and angle 40 to get -0.940 and 0.766. For the T1(y) and T2(y) I took sine of each angle to get 0.342 and 0.643. I converted mass of 100kg to -980N. Do I have that part right? And can you help me the rest of the way. I have spent two hours on this already. Thank you so much.

After this question, the only other one I'm stuck on is a ladder question. You have similar ones on this site, but not the same and I cant figure out what equation I should be using: A 10-kg ladder 2.5m long rests against a frictionless wall with its base on the floor 80cm from the wall. how much force does the top of the ladder exert on the wall?

- Physics -
**drwls**, Friday, April 22, 2011 at 10:57amLet's discuss the box and rope question. You should post the other one separately.

Since the angles that you were given are measured from vertical, you should use sine for the horizontal (x) components and cosine for the vertical (y) components. You have them mixed up.

You should write you equations in terms of T1 and T2, the two unknown tension forces you want to calculate.

When you substitute sines and cosines, you end up with

T1*sin 20 - T2*sin40 = 0

and

T1*cos 20 + T2*cos 40 = W = M g

0.3420 T1 - 0.6428 T2 = 0

0.9397 T1 + 0.7660 T2 = 100 * g

Don't forget to multiply the mass by g = 9.8 m/s^2 to get the tensions in newtons.

The rest is just algebra. Try substituting

T1 = 1.8794 T2

into the last equation and solving for T2

**Related Questions**

Physics - a 45N lithograph is supported by two wires. One wire makes a 25 angle ...

physics - A man weighing 500 newtons sits in swing suspended with two ropes if ...

physics - A basket weighing 0.3kg is suspended from two ropes which are tied to ...

physics - In a modern art exhibit, a multicolors empty industrial wire spool is ...

Physics - A box of mass 54.0 kg is sitting on a ramp which makes an angle of 37....

Physics - A crate (weight 381 N) is lowered vertically a distance of 3.0 m by ...

Physics - Charge on pith balls - Two pith balls equally charged and each with a ...

Physics - Consider the 676 N weight held by two cables shown below. The left-...

physics - Consider the 620 N weight held by two cables shown below. The left-...

Physics - "A 1220-N uniform beam is attached to a vertical wall at one end and ...