A pendulum which is suspended from the ceiling of a railroad car is observed to hang at an angle of 10 degrees

Q-1; Multiple Choice: A pendulum which is suspended from the ceiling of a railroad car is
observed to hang at an angle of 10 degrees to the right of vertical. Which of the following
answers could explain this phenomena?
w) The railroad car is at rest.
x) The railroad car is accelerating to the left.
y) The railroad car is moving with constant velocity to the right.
z) The railroad car is accelerating to the right.
ANSWER: X -- THE RAILROAD CAR IS ACCELERATING TO THE LEFT.

Q-2; Multiple Choice: Two forces have magnitudes of 11 newtons and 5 newtons. The
magnitude of their sum could NOT be equal to which of the following values?
w) 16 newtons
x) 5 newtons
y) 9 newtons
z) 7 newtons
ANSWER: X -- 5 NEWTONS

Q-3; Short Answer: A ball leaves a girl's hand with an upward velocity of 6 meters per
second. What is the maximum height of the ball above the girl's hand?
ANSWER: 1.8 METERS

Q-4; Short Answer: A boy throws a ball vertically upward with a velocity of 6 meters per
second. How long does it take the ball to return to the boy's hand?
ANSWER: 1.22 SECONDS (accept: 1.2 seconds)

Q-5; Short Answer: A toy train moves in a circle of 8 meters radius with a speed of 4
meters per second. What is the magnitude of the acceleration of the train?
ANSWER: 2 METERS PER SECOND SQUARED

Q-6; Short Answer: A certain machine exerts a force of 200 newtons on a box whose mass
is 30 kilograms. The machine moves the box a distance of 20 meters along a horizontal floor.
What amount of work does the machine do on the box?
ANSWER: 4000 JOULES