Hi,

There is something weird here:

Please look at problem and solution.

There is something weird here:

Please look at problem and solution.

When I set my equations:

2000a=2000gsin(30°)-T

1800a=-1800gsin(20°)+T

I add them up:

3800a=2000gsin(30°)-1800gsin(20°)

a=1m/s^2

Now I want to equilibriate the car:

The force of brakes=-2000a=-2000a=-2000N.

But the book has a different answer. I understand their method. But why is my method wrong? Please try to explain to me in detail clearly. I have difficulty understanding.

http://ift.tt/1sXwPw4