Quiz 1: Testing Your Knowledge of Force & Inertia

[Ab e r z o m]

http://physicsed.buffalostate.edu/c...anics/PDF files/4-FP-Inertia/Tests/Quiz 1.pdf

1) I don't know how to do this, but I know there is the force of gravity by the Earth in the force diagram..

2) For this one I got the answer
Fx=7.5N [I did 1/2(15N) which equals 7.5 N]
Fy=13N [I took my x component 7.5N and I did 7.5sqrt3=13N]
Did I solve this problem right??

3) How do you write an equation for this diagram?

Can you tell me if I did the Bonus right?

T1cos(60)=T2
T2sin(60)= 3kg

T1sin(60)=3kg
I divided both sides by sin(60) to make T1 by itself so
T1sin(60)/sin(60)=3.464
SO T1=3.464

I took T1=3.464 and plug it into T1cos(60)=T2
3.464cos(60)=T2
T2=1.232

So I don't know if I got that one right??
My answer is T1=3.464 and T2=1.232

Please help me..I really need this. Thank you!

 

[phyzmatix]

1) There is also a normal force and a kinetic frictional force.
2) You need to resolve your vector into components using trig.
3) The system seems to be in equilibrium, so

$$F_{xnet}=0$$

and

$$F_{ynet}=0$$

Start from there and re-think your strategy for the bonus part. For one, tension is a force so you can't measure it in kg...Remember Newton's second law.