Question

A body is projected horizontally with a velocity of $4\sqrt{2}$ m/sec. The velocity of the body after 0.7 seconds will be nearly: (Take $g=10m/se{c}^2$)

• A. 10 m/sec
• B. 9 m/sec
• C. 19 m/sec
• D. 11 m/sec

Answer 1

Answer: (B)

9 m/sec

Since only gravitational force acts on the object downwards, the horizontal component of velocity remains same=$v_x=4\sqrt{2}m/s$

Initially there is no vertical component of the velocity.

Thus the final velocity in vertical direction =$v_y=at=10\times 0.7m/s=7m/s$

Thus net velocity=$\sqrt{v_x^2+v_y^2}=9m/s$