Question

If cabin is decending vertically with acceleration a and action by mass M on floor of cabin is $\frac{9Mg}{10}$ then a equals to:

• A. $g$
• B. $\frac{g}{10}$
• C. $\frac{9}{10}g$
• D. $\frac{10}{9}g$

Answer 1

The correct option is B $\frac{g}{10}$

Given,

$R=\frac{9Mg}{10}$

$a=$ acceleration

$M=$ mass

The cabin is descending vertically then the reaction force is

$R=M(g-a)=Mg-Ma$

$\frac{9Mg}{10}=Mg-Ma$

$Ma=\frac{10Mg-9Mg}{10}=\frac{Mg}{10}$

$a=\frac{g}{10}$

The correct option is B.