Question

balanced/unbalanced forces practice problems
problem\tnet force equations (include direction of forces & label)\tbalanced or unbalanced? (circle answer)
1\thint: you will need two equations in some cases.\tbalanced unbalanced
2\tbalanced unbalanced
3\tbalanced unbalanced
4 force of boy (pulling) = 45 n right
force of girl (pushing) = 30 n right
friction force = 25 n left\tbalanced unbalanced
5 force of girl = 75 n left
gravitational force = 900 n down
normal force = 900 n up
friction force = 75 n right\tbalanced unbalanced

Explanation:

Step1: Calculate net - force horizontally and vertically for each problem

For problem 1:
Horizontally, the forces are 30 N to the left and 30 N to the right. The net - force in the x - direction $F_{x}=30 - 30=0$ N. Vertically, the forces are 25 N up and 20 N down. The net - force in the y - direction $F_{y}=25 - 20 = 5$ N. Since $F_{y}
eq0$, the forces are unbalanced.
For problem 2:
Horizontally, the forces are 30 N to the left, 30 N to the right and 14 N to the right. The net - force in the x - direction $F_{x}=30-(30 + 14)= - 14$ N. Vertically, the forces are 25 N up and 25 N down. The net - force in the y - direction $F_{y}=25 - 25=0$ N. Since $F_{x}
eq0$, the forces are unbalanced.
For problem 3:
Horizontally, the forces are 100 N to the right, 75 N to the left and 125 N to the left. The net - force in the x - direction $F_{x}=100-(75 + 125)=100 - 200=-100$ N. Since $F_{x}
eq0$, the forces are unbalanced.
For problem 4:
The forces to the right are $45+30 = 75$ N and the force to the left is 25 N. The net - force $F = 75-25 = 50$ N. Since $F
eq0$, the forces are unbalanced.
For problem 5:
Horizontally, the forces are 75 N to the left and 75 N to the right. The net - force in the x - direction $F_{x}=75 - 75=0$ N. Vertically, the gravitational force is 900 N down and the normal force is 900 N up. The net - force in the y - direction $F_{y}=900 - 900 = 0$ N. Since $F_{x}=0$ and $F_{y}=0$, the forces are balanced.

Step2: Fill in the net - force equations and balance status

Problem 1: Net - force equations: $F_{x}=0$ N, $F_{y}=5$ N. Unbalanced.
Problem 2: Net - force equations: $F_{x}=-14$ N, $F_{y}=0$ N. Unbalanced.
Problem 3: Net - force equations: $F_{x}=-100$ N. Unbalanced.
Problem 4: Net - force equation: $F = 50$ N. Unbalanced.
Problem 5: Net - force equations: $F_{x}=0$ N, $F_{y}=0$ N. Balanced.

Answer:

Problem	Net Force Equations (include direction of forces & label)	Balanced or Unbalanced?
2	$F_{x}=-14$ N, $F_{y}=0$ N	Unbalanced
3	$F_{x}=-100$ N	Unbalanced
4	$F = 50$ N (right)	Unbalanced
5	$F_{x}=0$ N, $F_{y}=0$ N	Balanced