How to solve the following problems? Please show steps and explanations.

3-5 and 3-6 Projectile Motion (neglect air resistance)

19) A fire hose held near the ground shoots water at a speed of 6.8 m/s. At what angle(s) should the nozzle point in order that the water land 2.0 m away? Why are there two different angles?

29) Suppose a kick is attempted 36 m from the goalposts, whose crossbar is 3 m above the ground. If the football is directed correctly between the goalposts, will it pass over the bar and be a field goal? Show why or why not.

31) A projectile is shot from the edge of a cliff 125 m above the ground level with an initial speed of 65 m/s at an angle of 37 degrees with the horizontal.

• (a) Determine the time taken by the projectile to hit point P at ground level.
• (b) Determine the unknown range of the projectile as measured from the base of the cliff
• (c) At the instant just before the projectile hits Point P, find the horizontal and the vertical components of its velocity
• (d) Find the magnitude of the velocity
• (e) Find the angle made by the velocity vector with the horizontal
• (f) Find the max height above the cliff top reached by the projectile

3-8 Relative Velocity

36) A person going for a morning jog on the deck of a cruise ship is running toward the bow (front) of the ship at 2.2 m/s while the ship is moving ahead at 7.5 m/s. What is the velocity of the jogger relative to the water? Later, the jogger is moving toward the stern (rear) of the ship. What is the jogger's velocity relative to the water now?

37) A person walks at a speed of 0.60 m/s across his raft (that is he walks perpendicular to the raft's motion relative to the shore). The raft is traveling down a river at a speed of 1.70 m/s relative to the river bank. What is Huck's velocity (speed and direction) relative to the river bank?

39) A boat can travel 2.3 m/s in still water.

• (a) If the boat points its prow directly across a stream whose current is 1.2 m/s, what is the velocity (magnitude and direction) of the boat relative to the shore?
• (b) What will be the position of the boat, relative to its point of origin, after 3 sec

47) A swimmer is capable of swimming 0.45 m/s in still water;

• (a) If she aims her body directly across a 75-m-wide river whose current is 0.40 m/s, how far downstream (from a point opposite her starting point) will she land?
• (b) How long will it take her to reach the other side?

41) An airplane is heading due south at a speed of 600 km/h.

• (a) If a wind begins blowing from the southwest of a speed of 100 km/h (average), calculate the velocity (magnitude and direction) of the plane relative to the ground
• (b) How far from its intended position will it be after 10 min if the pilot takes no corrective action. (First draw a diagram)