Exam 3: Motion in Two or Three Dimensions

A pilot drops a package from a plane flying horizontally at a constant speed.Neglecting air resistance,when the package hits the ground the horizontal location of the plane will

Jan and Len throw identical rocks off a tall building at the same time.The ground near the building is flat.Jan throws her rock straight downward.Len throws his rock downward and outward such that the angle between the initial velocity of the rock and the horizon is 30°.Len throws the rock with a speed twice that of Jan's rock.If air resistance is negligible,which rock hits the ground first?

A swimmer heading directly across a river 200 m wide reaches the opposite bank in during which time she is swept downstream 480 m. (a)How fast can she swim in still water? (b)What is the speed of the current?

A plane flying at 70.0 m/s suddenly stalls.If the acceleration during the stall is directly downward,the stall lasts 5.0 s,and the plane was originally climbing at 25° to the horizontal,what is the velocity after the stall?

A projectile returns to its original height 4.08 s after being launched,during which time it travels 76.2 m horizontally.If air resistance can be neglected,what was the projectile's initial speed?

An aircraft performs a maneuver called an "aileron roll." During this maneuver,the plane turns like a screw as it maintains a straight flight path,which sets the wings in circular motion.If it takes it 35 s to complete the circle and the wingspan of the plane is 11 m,what is the acceleration of the wing tip?

A boy throws a rock with an initial velocity of at 30.0° above the horizontal.If air resistance is negligible,how long does it take for the rock to reach the maximum height of its trajectory?

A projectile is fired from point 0 at the edge of a cliff,with initial velocity components of and ,as shown in the figure.The projectile rises and then falls into the sea at point P.The time of flight of the projectile is 40.0 s,and it experiences no appreciable air resistance in flight.What is the magnitude of the velocity of the projectile 21.0 s after it is fired?

Alice and Tom dive from an overhang into the lake below.Tom simply drops straight down from the edge,but Alice takes a running start and jumps with an initial horizontal velocity of 25 m/s.Neither person experiences any significant air resistance.Compare the time it takes each of them to reach the lake below.

The horizontal coordinates of a in a strong wind are given by where x and y are in meters,and t is in seconds. (a)What is the acceleration of the Frisbee? Give a magnitude and a direction,measuring angles from the positive x direction. (b)What is the magnitude of the velocity at accurate to the nearest

A monkey is sitting at the top of a tree 20 m above ground level.A person standing on the ground wants to feed the monkey.He uses a bow and arrow to launch the food to the monkey.If the person knows that the monkey is going to drop from the tree at the same instant that the person launches the food,how should the person aim the arrow containing the food? Air resistance is small enough to be ignored.

If an object travels at a constant speed in a circular path,the acceleration of the object is

A plane has an eastward heading at a speed of (relative to the air).A wind is blowing southward while the plane is flying.The velocity of the plane relative to the ground is

An object has a position given by = [2.0 m + (5.00 m/s)t] + [3.0 m - ,where quantities are in SI units.What is the speed of the object at time

Two particles,A and B,are in uniform circular motion about a common center.The acceleration of particle A is 8.5 times that of particle B.The period of particle B is 2.0 times the period of particle A.The ratio of the radius of the motion of particle A to that of particle B is closest to

A projectile is fired from point 0 at the edge of a cliff,with initial velocity components of and ,as shown in the figure.The projectile rises and then falls into the sea at point P.The time of flight of the projectile is ,and it experiences no appreciable air resistance in flight.What is the height of the cliff?

A child throws a ball with an initial speed of at an angle of 40.0° above the horizontal.The ball leaves her hand above the ground and experience negligible air resistance. (a)How far from where the child is standing does the ball hit the ground? (b)How long is the ball in flight before it hits the ground?

While an object is in projectile motion (with upward being positive)with no air resistance,

A wind farm generator uses a two-bladed propeller (see figure)mounted on a pylon at a height of 20 m.The length of each propeller blade is 12 m.A small piece from the tip of the propeller breaks off when the propeller is vertical.At that instant,the period of the motion of the propeller is .The fragment flies off horizontally,falls with negligible air resistance,and strikes the ground at P. (a)How far is point P from the base of the pylon? (b)At what angle with respect to the vertical is the fragment moving just as it strikes the ground at P?

Alice and Tom dive from an overhang into the lake below.Tom simply drops straight down from the edge,but Alice takes a running start and jumps with an initial horizontal velocity of 25 m/s.Neither person experiences any significant air resistance.Just as they reach the lake below,