To solve this problem, we can use the cosine formula for
calculating the length of the displacement:
c^2 = a^2 + b^2 – 2 a b cos θ
where c is the displacement, a = 3.5 km, b = 4.5 km, and θ
is the angle inside the triangle
Since the geeze turned 40° from west to north, so the
angle inside the triangle must be:
θ = 180 – 40 = 140°
c^2 = 3.5^2 + 4.5^2 – 2 (3.5) (4.5) cos 140
c^2 = 56.63
c = 7.53 km
<span>So the magnitude of the displacement is 7.53 km</span>
This is a problem that would be a good test of your understanding rather than your ability to work the formulas. 5m/s² means that the velocity increase each second is 5 m/s. So 4 s of that acceleration would increase the speed (in m/s) from 20 to 40. (Speed increase each second is 5 m/s. We need an increase of 20 m/s.)
Since the acceleration is uniform during those 4 s, we can use the simple average speed of 30 m/s. 30 m/s * 4 s = 120 m.
Free-body diagrams are diagrams used to show the relative magnitude and direction of all forces acting upon an object in a given situation. A free-body diagram is a special example of the vector diagrams
