Question 106: Laws of Motion

Question

An object of mass 5 kg is thrown vertically upwards from the ground. The air resistance produces a constant retarding force of 10 N throughout the motion. The ratio of time of ascent to the time of descent will be equal to : [Use g = 10 ms$$-$$2].

Accepted Answer

Let time taken to ascent is t
1
and that to descent is t
2
. Height will be same so
$$H = {1 \over 2} 	imes 12t_1^2 = {1 \over 2}	imes8t_2^2$$
$$ \Rightarrow {{{t_1}} \over {{t_1}}} = {{\sqrt 2 } \over {\sqrt 3 }}$$

Answer

1 : 1

Answer

$$\sqrt 2 $$ : $$\sqrt 3 $$

Answer

$$\sqrt 3 $$ : $$\sqrt 2 $$

Answer

2 : 3

Laws of Motion

An object of mass 5 kg is thrown vertically upwards from the ground. The air resistance produces a constant retarding force of 10 N throughout the motion. The ratio of time of ascent to the time of descent will be equal to : [Use g = 10 ms$-$2].

Choose the correct answer: