Answer to Question #87882 in Physics for Dirk McPherson

Question

From a point A, a body travels for 2s at a constant velocity of 12m/s due north. It then travels for 5s due east whilst its velocity decreases uniformly from 12m/s to 6m/s. What is the resultant displacement from A? Also determine the average velocity, in magnitude and direction, of the body for it to return along a straight path to point A in 3s.

Answer 1

$$v_{x,avg}=\frac{12+6}{2}=9 \frac{m}{s}$$

$$s_y=12(2)=24 m$$

$$s_x=9(5)=45 m$$

$$s=\sqrt{24^2+45^2}=51 m.$$

The direction is

$$a=\arctan{\frac{24}{45}}=28^\circ$$

north of east.

The direction, of the body for it to return along a straight path to point A in 3s is 28 degree south of west.

The magnitude is

$$V=\frac{51}{3}=17 \frac{m}{s}$$