Question 1

A ball is thrown straight upward with an initial velocity of $$15\ \mathrm{m/s}. $$Ignoring air resistance, what is the maximum height the ball reaches above its starting point? (Use $$g = 9.81\ \mathrm{m/s^2$}$$ downward.)

Accepted Answer

$$11.5\ \mathrm{m}$$

Question 2

A hot-air balloon is rising at a constant speed of $$6.5\ \mathrm{m/s}. $$When the basket is $$20.0\ \mathrm{m}$$ above the ground, a sandbag is dropped. How long does it take for the sandbag to hit the ground? (Take $$g = 9.81\ \mathrm{m/s^2$}$$ downward.)

Accepted Answer

$$2.79\ \mathrm{s}$$

Question 3

Which equation would you use to find the final velocity of an object in free fall, given its initial velocity, acceleration, and displacement?

Accepted Answer

$$v^2$$ = $$v_0^2 + 2a(x$$ - $$x_0$$)$$

Question 4

A lava bomb is ejected straight upward from a volcano with an initial velocity of $$23.3\ \mathrm{m/s}. $$How long does it take to return to its launch height? (Assume $$g = 9.81\ \mathrm{m/s^2$}$$ downward.)

Accepted Answer

$$4.75\ \mathrm{s}$$

Question 5

A model rocket accelerates upward at $$12\ \mathrm{m/s^2$}$$ from rest until it reaches $$29\ \mathrm{m}$$, then its engine shuts off and it continues in free fall. What is the rocket's speed just before it hits the ground? (Take $$g = 9.81\ \mathrm{m/s^2$}$$ downward.)

Accepted Answer

$$36\ \mathrm{m/s}$$

Question 6

A feather and an apple are dropped from the same height in a vacuum. Which statement is correct?

Accepted Answer

Both hit the ground at the same time because the acceleration due to gravity is the same for both.

Question 7

A ball is thrown downward from a height of $$50\ \mathrm{m}$$ with an initial speed of $$5\ \mathrm{m/s}. $$How long does it take to reach the ground? (Take $$g = 9.81\ \mathrm{m/s^2$}$$ downward.)

Accepted Answer

$$2.87\ \mathrm{s}$$

Question 8

Which of the following best describes the velocity of an object at the maximum height of its upward trajectory?

Accepted Answer

$$0\ \mathrm{m/s}$$

Question 9

A geologist observes a lava bomb that takes $$4.75\ \mathrm{s} to $$rise and fall back to its launch height. What was the initial speed of the bomb? (Assume $$g = 9.81\ \mathrm{m/s^2$}$$ downward.)

Accepted Answer

$$23.3\ \mathrm{m/s}$$

Question 10

An arrow is shot straight upward and reaches $$30.0\ \mathrm{m}$$ after $$2.00\ \mathrm{s}. $$What was its initial speed? (Take $$g = 9.81\ \mathrm{m/s^2$}$$ downward.)

Accepted Answer

$$24.8\ \mathrm{m/s}$$

Question 11

A sandbag is dropped from a hot-air balloon rising at $$6.5\ \mathrm{m/s}$$ from $$20.0\ \mathrm{m}$$ above the ground. What is the greatest height the sandbag reaches?

Accepted Answer

$$22.2\ \mathrm{m}$$

Question 12

Which kinematic equation would you use to solve for the displacement of an object given its initial velocity, acceleration, and time?

Accepted Answer

$$x = x_0$ + v_0$ t + \frac{1}{2} a t^2$

Question 13

A model rocket reaches a speed of $$26\ \mathrm{m/s} at$$ $$29\ \mathrm{m}$$ altitude before its engine shuts off. What is the maximum height it reaches? (Take $$g = 9.81\ \mathrm{m/s^2$}$$ downward.)

Accepted Answer

$$65\ \mathrm{m}$$

Question 14

A ball is thrown upward with an initial velocity $$v_0. $$Which of the following statements is true about its acceleration during its flight (ignoring air resistance)?

Accepted Answer

The acceleration is constant and equal to $$-9.81\ \mathrm{m/s^2$} at $$all times.

Question 15

A stone is dropped from rest from a cliff and takes $$3.0\ \mathrm{s} to $$reach the ground. What is the height of the cliff? (Take $$g = 9.81\ \mathrm{m/s^2$}$$ downward.)

Accepted Answer

$$44.1\ \mathrm{m}$$

Question 16

A ball is thrown straight upward and returns to the thrower's hand after $$6.0\ \mathrm{s}. $$What was the ball's initial velocity? (Take $$g = 9.81\ \mathrm{m/s^2$}$$ downward.)

Accepted Answer

$$29.4\ \mathrm{m/s}$$

One-Dimensional Kinematics: Freely Falling Objects and Constant Acceleration

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