Question

question 3
20 pts
a 40 kg box is pulled by two ropes: ↑125 n and ↑95 n. what is its acceleration?
○ 4.5 m/s² ↑
○ 6.0 m/s² ↑
○ 5.0 m/s² ↑
○ 5.5 m/s² ↑

Explanation:

Step1: Calculate net force

The two forces are acting in the same upward direction. So the net force $F_{net}=125 + 95=220$ N.

Step2: Use Newton's second - law

Newton's second - law is $F = ma$, where $F$ is the net force, $m$ is the mass and $a$ is the acceleration. We need to solve for $a$, so $a=\frac{F_{net}}{m}$. Given $m = 40$ kg and $F_{net}=220$ N. Then $a=\frac{220}{40}=5.5$ m/s².

Answer:

$5.5$ m/s² $\uparrow$