Answer to Question #95169 in Classical Mechanics for Lauren Wright

Question

A body of mass 2.60 kg is pushed straight upward by a 31.2 N vertical force. What is it’s acceleration?

Answer 1

Newton's second Law is applied to the body.

$F_{Net}=m*a$

Where

• The object's mass $m=2.60kg$
• Acceleration a$a$

But the net force is equal to the sum of the forces

$F_{Net}=\sum F \\ F_{net}=F-W$

Where:

External force $F=31.2Nw$

The weight is $W=m*g \\ W=2.60kg*9.81\frac{m}{s^{2}}\\W=25.5Nw$

Combining expressions

$m*a=F-W$

Expression for acceleration.

$m*a=F-W \\a=\frac{F-W}{m}$

Numerically evaluating

$a=\frac{32.5Nw-25.5Nw}{2.60kg}=2.69\frac{m}{s^{2}}$

The acceleration of the object is

$\boxed{a=2.69\frac{m}{s^{2}}}$