Chapter 3 -Kinematics in Two Dimensions; Vectors Flashcards
(10 cards)
If a vector pointing upward has a positive magnitude, a vector pointing downward has a negative magnitude.
A) True
B) False
B) False
Two displacement vectors have magnitudes of 5.0 m and 7.0 m, respectively. If these two vectors are added together, the magnitude of the sum
A) is equal to 2.0 m.
B) could be as small as 2.0 m or as large as 12 m.
C) is equal to 12 m.
D) is equal to 8.6 m.
B) could be as small as 2.0 m or as large as 12 m.
The magnitude of the resultant of two vectors cannot be less than the magnitude of either of those two vectors.
A) True
B) False
B) False
If a vector’s components are all negative, then the magnitude of the vector is negative.
A) True
B) False
B) False
A boulder rolls off of a very high cliff and experiences no significant air resistance. While it is falling, its trajectory is never truly vertical.
A) True
B) False
A) True
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) The speed of the object is constant but its velocity is not constant.
B) The acceleration of the object is +g when the object is rising and -g when it is falling.
C) The acceleration of the object is zero at its highest point.
D) The speed of the object is zero at its highest point.
E) The horizontal acceleration is always zero and the vertical acceleration is always a non-zero
constant downward.
E) The horizontal acceleration is always zero and the vertical acceleration is always a non-zero
constant downward.
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
A) be behind the package.
B) be directly over the package.
C) be in front of the package.
D) depend on the speed of the plane when the package was released.
B) be directly over the package.
James and John dive from an overhang into the lake below. James simply drops straight down from the edge. John takes a running start and jumps with an initial horizontal velocity of 25 m/s. If there is no air resistance, when they reach the lake below
A) the splashdown speed of James is larger than that of John.
B) the splashdown speed of John is larger than that of James.
C) they will both have the same splashdown speed.
D) the splashdown speed of James must be 9.8 m/s larger than that of John.
E) the splashdown speed of John must be 25 m/s larger than that of James.
B) the splashdown speed of John is larger than that of James.
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 30° above 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.)
A) Debra’s snowball will stay in the air longer than Mary’s snowball.
B) Mary’s snowball will stay in the air longer than Debra’s snowball.
C) Both snowballs will take the same amount of time to hit the ground.
D) Debra’s snowball has exactly the same acceleration as Mary’s snowball.
E) Mary’s snowball has a greater downward acceleration than Debra’s snowball.
A) Debra’s snowball will stay in the air longer than Mary’s snowball.
D) Debra’s snowball has exactly the same acceleration as Mary’s snowball.
A player kicks a soccer ball in a high arc toward the opponent’s goal. At the highest point in its trajectory
A) both the velocity and the acceleration of the soccer ball are zero.
B) neither the ball’s velocity nor its acceleration are zero.
C) the ball’s acceleration is zero but its velocity is not zero.
D) the ball’s acceleration points upward.
E) the ball’s velocity points downward.
B) neither the ball’s velocity nor its acceleration are zero.
