Exam 3: Kinematics in Two Dimensions

A tennis ball is thrown upward at an angle from point A.It follows a parabolic trajectory and hits the ground at point D.At the instant shown, the ball is at point B.Point C represents the highest position of the ball above the ground. -While in flight, how do the x and y components of the velocity vector of the ball compare at the points A and D?

A toolbox is carried from the base of a ladder at point A as shown in the figure.The toolbox comes to a rest on a scaffold 5.0 m above the ground.What is the magnitude of the displacement of the toolbox in its movement from point A to point B?

3-1 During a one-hour trip, a small boat travels 80.0 km north and then travels 60.0 km east. -What is the magnitude of the boat's average velocity for the one-hour trip?

3-4 A projectile fired from a gun has initial horizontal and vertical components of velocity equal to 30 m/s and 40 m/s, respectively. -What is the speed of the projectile when it is at the highest point in its trajectory?

3-12 A man at point A directs his rowboat due north toward point B, straight across a river of width 100 m.The river current is due east.The man starts across, rowing steadily at 0.75 m/s and reaches the other side of the river at point C, 150 m downstream from his starting point. -A passenger at rest on a flatbed train car fires a bullet straight up.The event is viewed by observers at rest on the station platform as the train moves past the platform with constant velocity.What is the trajectory of the bullet as described by the observers on the platform?

3-4 A projectile fired from a gun has initial horizontal and vertical components of velocity equal to 30 m/s and 40 m/s, respectively. -Determine the initial speed of the projectile.

A ball is fired at an angle of 45°, the angle that yields the maximum range in the absence of air resistance.What is the ratio of the ball's maximum height to its range?

3-3 A projectile is fired at an angle of 55.0° above the horizontal with an initial speed of 35.0 m/s. -How long does it take the projectile to reach the highest point in its trajectory?

3-2 A spaceship is observed traveling in the positive x direction with a speed of 150 m/s when it begins accelerating at a constant rate.The spaceship is observed 25 s later traveling with an instantaneous velocity of 1500 m/s at an angle of 55° above the +x axis. -What was the magnitude of the acceleration of the spaceship during the 25 seconds?

3-1 During a one-hour trip, a small boat travels 80.0 km north and then travels 60.0 km east. -What is the boat's displacement for the one-hour trip?

A physics student standing on the edge of a cliff throws a stone vertically downward with an initial speed of 10.0 m/s.The instant before the stone hits the ground below, it is traveling at a speed of 30.0 m/s.If the physics student were to throw the rock horizontally outward from the cliff instead, with the same initial speed of 10.0 m/s, what is the magnitude of the velocity of the stone just before it hits the ground?

3-5 A shell is fired with a horizontal velocity in the positive x direction from the top of an 80-m high cliff.The shell strikes the ground 1330 m from the base of the cliff.The drawing is not to scale. -What is the magnitude of the acceleration of the shell just before it strikes the ground?

A tennis ball is thrown from ground level with velocity directed 30° above the horizontal.If it takes the ball 0.5 s to reach the top of its trajectory, what is the magnitude of the initial velocity?

A football is kicked at an angle $\theta$ with respect to the horizontal.Which one of the following statements best describes the acceleration of the football during this event if air resistance is neglected?

3-5 A shell is fired with a horizontal velocity in the positive x direction from the top of an 80-m high cliff.The shell strikes the ground 1330 m from the base of the cliff.The drawing is not to scale. -Determine the initial speed of the shell.

A projectile is fired horizontally with an initial speed of 50.0 m/s.Neglect air resistance. -What is the magnitude of the acceleration of the projectile 3.00 s after it is fired?

3-4 A projectile fired from a gun has initial horizontal and vertical components of velocity equal to 30 m/s and 40 m/s, respectively. -At what angle is the projectile fired (measured with respect to the horizontal)?

A puck slides across a smooth, level tabletop at height H at a constant speed v_o.It slides off the edge of the table and hits the floor a distance x away as shown in the figure. What is the relationship between the distances x and H?

3-4 A projectile fired from a gun has initial horizontal and vertical components of velocity equal to 30 m/s and 40 m/s, respectively. -A quarterback throws a pass at an angle of 35° above the horizontal with an initial speed of 25 m/s.The ball is caught by the receiver 2.55 seconds later.Determine the distance the ball was thrown.

At time t = 0 s, a puck is sliding on a horizontal table with a velocity 3.60 m/s, 35.0° above the +x axis.As the puck slides, a constant acceleration acts on it that has the following components: a_x = -0.360 m/s² and a_y = -0.980 m/s².What is the velocity of the puck at time t = 1.50 s?