Question 1

At point Q on the go-kart track (see image), the driver is speeding up while turning. Which of the following best describes the directions of the velocity and acceleration vectors at this point?

Accepted Answer

Velocity is tangent to the track; acceleration has both a tangent component (forward) and a normal component (toward the center of curvature).

Question 2

A toy car moves along a straight track. At point B on its position vs. time graph, the slope of the car's curve is steeper than that of a toy truck moving on a parallel track. What does this indicate about their speeds at point B?

Accepted Answer

The toy car's speed is greater than the toy truck's speed.

Question 3

A go-kart starts from rest at point P and reaches a speed of $$12\ \mathrm{m/s} at $$point Q after $$15\ \mathrm{s}. $$What is the average acceleration of the go-kart during this interval?

Accepted Answer

$$0.8\ \mathrm{m/s^2$}$$

Question 4

For a full lap around the go-kart track, what is the average velocity of the go-kart if it starts and ends at the same point?

Accepted Answer

$$0$$

Question 5

Which two pieces of information are needed to determine the average speed for a full lap around the go-kart track?

Accepted Answer

The perimeter of the track and the lap time

Question 6

Ball Q is released from rest and falls for $$0.40\ \mathrm{s}$$ before colliding with ball P. How far does ball Q fall before the collision? (Assume $$g = 9.8\ \mathrm{m/s^2$})$$

Accepted Answer

$$0.78\ \mathrm{m}$$

Question 7

Given the scenario in the billiard ball diagram, what is the initial speed $$v_0$$ required for ball P to collide with ball Q after $$0.40\ \mathrm{s}$$?

Accepted Answer

$$10\ \mathrm{m/s}$$

Question 8

Just before ball P hits ball Q, what is the magnitude and direction of ball P’s velocity? (Direction as an angle above horizontal)

Accepted Answer

$$6.9\ \mathrm{m/s}$$, $$43.5^\circ$$ above horizontal

Question 9

An apple dropped from a tall building on Earth falls a distance $$d in$$ $$2\ \mathrm{s}. In $$terms of $$d$$, how far will it have fallen after $$6\ \mathrm{s}$$?

Accepted Answer

$$9d$$

Question 10

On a planet where gravity is $$12$$ times stronger than on Earth, how long does it take for an apple to fall a distance $$d/3 ($$where $$d is $$the distance fallen in $$2\ \mathrm{s} on $$Earth)?

Accepted Answer

$$\frac{1}{3}\ \mathrm{s}$$

Question 11

At point S on the go-kart track, the driver is slowing down while turning. Which of the following best describes the acceleration vector at this point?

Accepted Answer

It has a component toward the center of curvature and a component opposite to the direction of motion.

Question 12

A position vs. time graph for a toy car shows a horizontal tangent at point C. What does this indicate about the car’s velocity at point C?

Accepted Answer

The velocity is zero.

Question 13

If the acceleration of a toy car is negative at a certain point, which of the following must be true?

Accepted Answer

The car’s velocity is decreasing if it is moving in the positive direction.

Question 14

A projectile is launched at an angle of $$60^\circ$$ above the horizontal. Which of the following best describes the vertical acceleration during its flight (neglecting air resistance)?

Accepted Answer

It is constant and equal to $$-g.$$

Question 15

Which of the following is true about the average velocity and average speed for a complete lap around a closed track?

Accepted Answer

Average velocity is zero, but average speed is nonzero.

PHY 220 Midterm 1 Review: 2D and Projectile Motion Guidance

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