Which of the following statements about projectile motion ARE correct? 1. The direction of both velocity and acceleration are changing across the motion trajectory 2. For a free fall object(the horizontal component of the initial velocity is zero), its velocity is zero when it reaches maximum height, but its acceleration is not zero at the same time.   3. The velocity direction is changing across the motion trajectory, but the acceleration direction remains the same.   4. For a free fall object(the horizontal component of the initial velocity is zero), both its velocity and acceleration are zero when it reaches maximum height.

24. A rocket is fired upward on a straight upward trajectory at 90 degrees to the surface perfectly, starting from rest with an acceleration of +29.4 m/s² for the first 4 seconds of travel. After finishing these 4 seconds it runs out of gas but continues its upward movement on its original path for a short time. a. b. What is the maximum height it reaches? If after reaching the maximum height it is allowed to fall in free fall in a perfectly linear path towards the earth, what is its final speed just before hitting the ground? Select one: - b. a. Maximum height = 135.8 meters, final velocity = 940.8 meters/seconds Maximum height = 940.8 centimeters, final velocity = 135.8 centimeters/seconds c. Maximum height = 940.8 centimeters, final velocity = 13.58 meters/seconds d. Maximum height = 940.8 meters, final velocity = 135.8 meters/seconds

A projectile is launched from ground level at a velocity of 28 m/s and an initial angle of 37 degrees. What is the projectile's velocity the instant before it hits the ground? Include a drawing and all steps. Use the projectile motion equations.

3. A rock is thrown with a speed of 30 m/s at an angle of 35° above the horizontal. A vertical wall is located 25 m away. How long will it take for the rock to hit the wall? How high up the wall does the rock strike the wall? What are the rock's velocity components when it strikes the wall? Does the rock strike the wall on its way up or its way down? 4 a) t = 1.02 s b) y = 12.4 m c) v = (24.6î +7.24ĵ) m/s d) On the way up!

1. According to legend, George Washington threw a silver dollar across the Potomac River, which is about 1600 m (1 mile) wide. For this problem, assume projectile motion and that the quarter was thrown at an angle of 45° and it landed at the same height it was thrown. A. How fast would he have had to throw the silver dollar to make it across the Potomac? B. Assess your answer from part a). Does this seem like a plausible feat?

Question 3