Question

What is the frictional force on a body by air which is falling through air at an acceleration of 9.2m/s^2? (mass=0.25kg and g=9.8)

Answer 1

Question#20823

What is the frictional force on a body by air which is falling through air at an acceleration of $9.2\mathrm{m/s^2}$? (mass=0.25kg and g=9.8)

Solution:

Let:

$$a = 9.2 \, \mathrm{m/s^2}$$ $$m = 0.25 \, \mathrm{kg}$$ $$F_f - ?$$

According to the second Newton's law:

$$a = \frac{F}{m}$$

$F = F_g - F_f$, where $F_g$ is the gravitational force, $F_f$ is frictional force

$$F_f = F_g - F$$ $$F_f = mg - ma = m(g - a)$$ $$F_f = 0.25(9.8 - 9.2) = 0.15 \, \mathrm{N}$$

Answer: 0.15 N.