Exam 3: Motion in Two Dimensions

A rifle bullet is fired at an angle of 30° below the horizontal with an initial velocity of 800 m/s from the top of a cliff 80 m high. How far from the base of the cliff does it strike the level ground below?

Consider two vectors A and B in Figure 3-3: The difference A-B is

Consider throwing a shotput at a 45.° elevation. The ratio of range to height (R/h) would be

If A+B= C and A+B=C, then the vectors A and B are oriented perpendicular relative to one other.

An airplane is pointed in the NE direction and is moving 71. m/s with respect to the air. The jetstream (moving air) carries the plane 30. m/s toward the East. What is the velocity of the plane relative to the ground?

Your motorboat can move at 30 km/h in still water. How much time will it take you to move 12 km upstream, in a river flowing at 6 km/h?

A fighter plane moving 200 m/s fires a projectile with speed 50 m/s in a forward direction. The projectile makes an angle of 30° with the direction of the plane's motion. What is the speed of the projectile with respect to a stationary observer on the ground?

Which of the following is a unit-vector?

You throw a pebble upward as shown, with a velocity v_o at an angle ?, from a roof (at point J) Figure 3-6 If the pebble rises upward to h ft above the roof (to point K), then falls to the ground below (to point L), its speed when it hits the ground is

A displacement vector is 34.0 m in length and is directed 60.0° east of north. What are the components of this vector?

You hit a tennis ball over the net. When the ball reaches its maximum height, its speed is

A marble rolls off the edge of a table top with a speed of 2.0 m/s. What is the magnitude of its velocity 0.10 s later?

Three vectors, expressed in Cartesian coordinates, are The magnitude of the resultant vector is

Misty throws a stone horizontally from the roof edge of a 50. meter high dormitory. It hits the ground at a point 60. m from the building. (a) Determine the horizontal component of velocity just before hitting the ground. (b) What vertical speed did it have just before hitting the ground?

A motorcycle stunt rider wants to jump a 179. m wide canyon. He arranges a ramp on one side so he will be launched pointed 30.° above the horizontal. What minimum speed will be needed to just reach the other side?

On a calm day (no wind), you can run a 1500-m race at a velocity of 4.0 m/s. If you ran the same race on a day when you had a constant tailwind of 2.0 m/s, the time it would take you to finish would be

John can hit a golf ball 310. m on Earth. On the moon's surface, g = ^g earth, so how far could he hit the same ball if he could only achieve half the initial speed at the same angle as that achieved on Earth?

Bullet G is dropped, from rest, at the same time that another bullet H is fired horizontally from a rifle. If both bullets leave from the same height above the ground, then

A player throws a football 50.0 m at 61.0° north of west. The westward component of the displacement of the football thrown is given by

A girl throws a rock horizontally with a speed of 12.0 m/s from a bridge. It falls 2.28 s before reaching the water below. (a) How high is the bridge from the water below? (b) How far horizontally does the rock travel before striking the water?