- Home
- Standard 9
- Science
7. MOTION
hard
Prove that if a body is thrown vertically upward, the time of ascent is equal to the time of descent.
Option A
Option B
Option C
Option D
Solution
For upward motion
$v=u-g t$ or $0=u-g t_{1}$
or $t_{1}=\frac{u}{g}$ $….(1)$
For downward motion
$v=u+g t_{2}$ or $v=0+g t_{2}$
As the body falls back to the earth with the same velocity, it was thrown vertically upwards.
$\therefore \quad v=u$
$u=0+g t_{2}$ or $t_{2}=\frac{u}{g}$ $…(2)$
From $(1)+(2)$ the statement is proved.
Standard 9
Science
