correctly, Summer 22/23.
Rock X is released from rest at the top of a cliff that is on Earth. A short time later,
Rock Y is released from rest from the same location as Rock X. Both rocks fall for
several seconds before landing on the ground directly below the cliff. Frictional
forces are considered to be negligible.
Which of the following graphs correctly shows the vertical velocity of rock X as a
function of time? Take the positive direction to be upward.
negative slope, straight line, has a point at the origin
Rock X is released from rest at the top of a cliff that is on Earth. A short time later,
Rock Y is released from rest from the same location as Rock X. Both rocks fall for
several seconds before landing on the ground directly below the cliff. Frictional
forces are considered to be negligible.
Which of the following graphs best represents the vertical displacement of Rock
X as a function of time starting from immediately after the rock is released from
rest? Take the positive direction to be downward.
smiley parabola with a point at the origin
Rock X is released from rest at the top of a cliff that is on Earth. A short time later,
Rock Y is released from rest from the same location as Rock X. Both rocks fall for
several seconds before landing on the ground directly below the cliff. Frictional
forces are considered to be negligible.
After Rock Y is released from rest several seconds after Rock X is released from
rest, what happens to the separation distance S between the rocks as they fall but
before they reach the ground, and why? Take the positive direction to be
downward.
S increases because at all times Rock X falls with a greater speed than Rock Y.
Toy car W travels across a horizontal surface with an acceleration of aw after
starting from rest. Toy car Z travels across the same surface toward car W with
an acceleration of az after starting from rest. Car W is separated from car Z by a
distance d. Which of the following pairs of equations could be used to determine
the location on the horizontal surface where the two cars will meet, and why?
x=x0+v0xt+12axt2 for car WW, and x=x0+v0xt+12axt2 for car Z. Since the cars will
meet at the same time, solving for t in one equation and placing the new expression for t
into the other equation will eliminate all unknown variables except x.
A ball traveling at a speed ν0 rolls off a desk and lands at a horizontal distance x0
away from the desk, as shown in the figure. The ball is then rolled off of the same
desk at a speed of 3 v0. At what horizontal distance will the ball land from the
table?
3x0
A student drops a rock from rest at a distance h above the ground such that the
rock hits the ground at time t0. At what distance above the ground should the
rock be dropped such that it hits the ground at a time 2t0 after it is released from
rest?
4h