Exam 3: Kinematics in Two Dimensions; Vectors

A pickup truck moves at 25 m/s toward the east. Ahmed is standing in the back and throws a baseball in what to him is the southwest direction at 28 m/s (with respect to the truck). A person at rest on the ground would see the ball moving how fast in what direction?

A projectile is thrown upward at 24 ° with the vertical and returns to the horizontal ground 12.5 s later with no air drag. (a) How fast was it thrown? (b) How far from its original position did it land? (c) How high above its original position did it go?

The components of vectors and are given as follows: The angle (less than 180°) between vectors is closest to

You walk 33 m to the north, then turn to your right and walk another 45 m. How far are you from where you originally started?

As shown in the figure, a projectile is fired at time t=0.00 s, from point 0 at the upper edge of a cliff, with initial velocity components of The projectile rises and then falls into the sea at point P . The time of flight of the projectile is 75.0 s, and air resistance is negligible. At this location, What is the horizontal distance D ?

A celebrating student throws a water balloon horizontally from a dormitory window that is 50 m above the ground. It hits the ground at a point 60 m from the building without appreciable air resistance. (a) What will be the horizontal component of the velocity of the balloon just before it hits the ground? (b) What will be the magnitude of the vertical velocity of the balloon just before it hits the ground?

A 960-m wide river flows at 16 m/s as shown in the figure. Alice and John have a race in identical boats which each travel 20 m/s in still water. Alice leaves point A and steers so that she goes straight to point B directly across and then back to A. John leaves point A and steers up to point C (960 m upstream) and then returns to A. (a) Which person arrives back at point A first? (b) How much sooner than the loser does the winner arrive back at point A?

The figure shows a 100-kg block being released from rest from a height of 1.0 m. It then takes 0.53 s for it to reach the floor. What is the mass m of the block on the left? There is no friction or mass in The pulley, and the connecting rope is very light.

A hobbyist launches a projectile from ground level on a horizontal plain. It reaches a maximum height of 72.3 m and lands 111 m from the launch point, with no appreciable air resistance. What Was the angle of launch if g = 9.80 m/s²?

Vector has a magnitude of 6.0 m and points south of east. Vector has a magnitude of 4.0 m and points west of south. The resultant vector is given by

The magnitude of a vector can never be less than the magnitude of any of its components.

Consider two vectors shown in the figure. The difference is best illustrated by

Three vectors, , have the components shown in the table. What angle does the resultant of these three vectors make with the

If a vector has components then the angle that this vector makes with the positive x -axis must be in the range

Vector has a magnitude of 4.0 m and points south of east. Vector has a magnitude of 2.0 m and points north of west. The resultant vector is given by

A hockey puck slides off the edge of a horizontal platform with an initial velocity of 28.0 m/shorizontally in a city where the acceleration due to gravity is 9.81 m/s². The puck experiences No significant air resistance as it falls. The height of the platform above the ground is 2.00 m. What Is the angle below the horizontal of the velocity of the puck just before it hits the ground?

A boy jumps with a velocity of magnitude 20.0 m/s at an angle of above the horizontal. What is the horizontal component of the boy's velocity?

An object slides on a level floor. It slows and comes to a stop with a constant acceleration of magnitude 2.4 m/s². What is the coefficient of kinetic friction between the object and the floor?

The sum of two vectors of fixed magnitudes has the greatest magnitude when the angle between these two vectors is

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 as the snowballs reach the ground below? (There could be More than one correct choice.)