Question

A body starts from the origin with an acceleration of 6 m/s² along the x-axis and 8 m/s² along the y-axis. Its distance from the origin after 4 seconds will be

• A. 56 m
• B. 64 m
• C. 80 m
• D. 128 m

Answer 1

Answer: (C)

80 m

Answer 2

Displacement along X- axis : $x = u_{x}t + \frac{1}{2}a_{x}t^{2}$

$= \frac{1}{2} \times 6 \times (4)^{2} = 48m$

Displacement along Y- axis :

$y = u_{y}t + \frac{1}{2}a_{y}t^{2} = \frac{1}{2} \times 8 \times (4)^{2} = 64m$

Total distance from the origin

$= \sqrt{x^{2} + y^{2}} = \sqrt{(48)^{2} + (64)^{2}} = 80m$