The speed of a boat in still water is v. A river flows with a speed of vr. The boat travels distance of 25 miles downstream in a river in 1 hour. However, the return journey takes 2 hours. Calculate the vand v Hint: Velocity = displacement/time. Displacement can be positive of neagtive depending on the direction. You will first need to set up the equations by taking into account the resultant velocity of the boat in flowing water. Consider the direction the river is flowing to be positive. Set up two equations, one for the downstream journey and one for the upstream journey, in terms of "v" and "v": Do v" and "v, add or substract downstream to give the resultant downstream velocity? Do vb" and "v, add or substract upstream togive the resultant upstream velocity? Use the upstream direction as negative. The resultant upstream velocity should be negative.

A certain person walks 80 cm north, 60 cm south and 30 cm north. What is the displacement? size of the displacement _______  direction of the displacement  ________

Crowdmark P MyLab & Masterin... N CAESAR - Northw... P GEN_ENG_205-1 (... onds ago BIU A 三三三三 1三三▼m▼三E 5... I 9. At t=0, a soccer ball is kicked due east (use the positive direction of the x x-axis as the eastward direction). Its initial speed is 10 m/s and its initial angle is 30 degrees above the horizontal. Due to strong westerly wind and the effect of gravitation, the acceleration of the soccer ball is a(1)=(-kt,-g), a(t)=(-kt,-g), where k is a positive constant. (a) Find the velocity v(t) of the ball. (b) Find the position vector r(t) of the ball. (c) Suppose that the ball lands back at the kicker's feet, exactly where it started. Find the value of the constant k. For ease of computation, we are using g=10 m/s2 m/s2.

A teacher drives his car at 3 mi N 40o E, then turns 3.8 mi to the West. What is the magnitude and direction of the teacher’s displacement from the starting position?