MCQ
A body is projected horizontally from a height with speed $20$ metres/sec. ........ $metres/sec$ will be its speed after $5$ seconds ($g = 10\,\,metres/{\sec ^2})$
- ✓$54$
- B$20$
- C$50$
- D$70$
✓
Answer
Correct option: A.
$54$
a
(a) Horizontal velocity ${v_x} = 20\,m/s$
(a) Horizontal velocity ${v_x} = 20\,m/s$
Vertical velocity ${v_y} = u + gt = 0 + 10 \times 5 = 50\,m/\sec $
Net velocity $v = \sqrt {v_x^2 + v_y^2} = \sqrt {{{(20)}^2} + {{(50)}^2}} $ $= 54 \,m/s.$
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