A 70-N block and an 35-N block are connected by a string as shown. If the pulley is massless and the surface is frictionless, the magnitude of the acceleration of the 35-N block is: A) 1.6 m/s² B) 3.3 m/s² C) 4.9 m/s² D) 6.7 m/s² E) 9.8 m/s²

Question

Quizplus · Accepted Answer

Since the pulley is massless and the surface is frictionless, we can assume that the tension in the string is the same throughout. Therefore, we can use Newton's second law for both blocks:
For the 70-N block:
$70 N - T = 70 a$
For the 35-N block:
$T - 35 N = 35 a$
Adding the two equations together, we get:
$35 N = 105 a$
Therefore, the acceleration of the 35-N block is:
$a = \frac{35 N}{105} = 0.33 m/s^2$

So, the correct choice is B.

A 70-N Block and an 35-N Block Are Connected by a String