Exam 3: Kinematics in Two Dimensions; Vectors

You push on box G that is next to box H, causing both boxes to slide along the floor, as shown in the figure. The reaction force to your push is

Displacement vector is 5.5 cm long and points along the +x -axis. Displacement vector is 7.5 cm long and points at to the - x -axis. (a) Determine the x and y components of vector (b) Determine the x and y components of vector (c) Determine the x and y components of the resultant of these two vectors. (d) Determine the magnitude and direction of the resultant of these two vectors.

Three ropes are tied in a knot as shown in the figure. One student pulls on rope A with 1.0 pound of force, and another student pulls on rope B with 7.0 pounds of force. How hard and in what direction must you pull on rope C to balance the first two pulls? Give the direction by specifying the angle (clockwise or counterclockwise) of the

A projectile is fired from ground level with an initial speed of 55.6 m/s at an angle o above the horizontal. Neglect air resistance, take upward as the positive direction, and use (a) Determine the time necessary for the projectile to reach its maximum height. (b) Determine the maximum height reached by the projectile. (c) Determine the horizontal and vertical components of the velocity vector at the maximum height. (d) Determine the horizontal and vertical components of the acceleration vector at the maximum height.

Refer to the figure, which shows four vectors , and . (a) Vector as expressed in terms of vectors and is given by A) B) C) (b) Vector as expressed in terms of vectors and is given by A) B) C)

An airplane is pointed a north of east and is moving at 71 m/s with respect to the air. The jet stream (moving air) carries the plane at 30 m/s toward the east. What are the magnitude and direction of the velocity of the plane relative to the ground?

A girl throws a rock horizontally, with a velocity of 10 m/s, from a bridge. It falls 20 m to the water below. How far does the rock travel horizontally before striking the water, assuming negligible air Resistance?

Which of the following statements are true about an object in two-dimensional projectile motion with no air resistance? (There could be more than one correct choice.)

A player throws a football 50.0 m at 61.0° north of west. What is the westward component of the displacement of the football?

Vector has magnitude 2 units and is directed to the north. Vector has magnitude 5 units and is directed to the south. Calculate the magnitude and direction of

Your motorboat can move at 30 km/h in still water. What is the minimum time it will take you to move 12 km downstream in a river flowing at 6.0 km/h?

A 55-kg box rests on a horizontal surface. The coefficient of static friction between the box and the surface is 0.30, and the coefficient of kinetic friction is 0.20. What horizontal force must be applied to the box to cause it to start sliding along the surface?

The magnitude of is 5.5 m, and this vector lies in the second quadrant and makes an angle of 34 - with the +y -axis. The components of are closest to:

A marble moving 1.48 m/s rolls off the top edge of a 125-cm high table in a room where there is no appreciable air resistance and the acceleration due to gravity is 9 (a) How far from the base of the table will it strike the floor? (b) How long will it be in the air?

A locomotive is pulling three train cars along a level track with a force of 100,000 N. The car next to the locomotive has a mass of 80,000 kg, the next one, 50,000 kg, and the last one, 70,000 kg. You can neglect the friction on the cars being pulled. (a) What is the magnitude of the force between that the 80,000-kg car exerts on the 50,000-kg car? (b) What is the magnitude of the force that the 50,000-kg car exerts on the 70,000-kg car?

Three forces, all act on an object, as shown in the figure. The magnitudes of the forces are: The resultant force acting on the object is given by

A hunter points a rifle horizontally and holds it 3.30 m above the ground. The bullet leaves the barrel at 325 m/s and experiences no significant air resistance. The acceleration due to gravity at this location (a) How long does it take for the bullet to strike the ground? (b) How far horizontally does it travel?

Mary and Debra stand on a snow-covered roof. They both throw snowballs with the same initial speed, but in different directions. Mary throws her snowball downward, at 30° below the Horizontal; Debra throws her snowball upward, at bove the horizontal. Which of the Following statements are true about just before the snowballs reach the ground below? (There Could be more than one correct choice.)

The acceleration due to gravity on the Moon is only one-sixth of that on Earth, and the Moon has no atmosphere. If you hit a baseball on the Moon with the same effort (and therefore at the speed And angle) as on Earth, how far would the ball would travel on the Moon compared to on Earth? Neglect air resistance on Earth.

An athlete participates in an interplanetary discus throw competition during an Olympiad that takes place on a planet where the acceleration due to gravity is He throws the discus with An initial velocity of 20 m/s at an angle of 6 ° from the vertical. Neglecting air resistance and the Height of the discus at the point of release, what is the range of the discus?