Question 1

Which of the following statements best describes a reference frame in physics?

Accepted Answer

A reference frame is a coordinate system, origin, clock, and observer used to measure position, distance, or speed relative to a chosen point.

Question 2

A car moves from $$x_1 = -30$$\ \mathrm{m}$$ to x_2$ = 20\ \mathrm{m}. $$What is its displacement?

Accepted Answer

$$\Delta x = 50\ \mathrm{m}$$

Question 3

A runner moves from $$x_1 = 50.0$$\ \mathrm{m}$$ to x_2$ = 30.5\ \mathrm{m} in$$ $$3.00\ \mathrm{s}. $$What is the runner's average velocity?

Accepted Answer

$$v_{av} = -6.50\ \mathrm{m/s}$$

Question 4

Which of the following correctly distinguishes between distance and displacement?

Accepted Answer

Distance is measured along the actual path traveled, while displacement is the straight-line change from initial to final position.

Question 5

A cyclist travels at an average speed of $$18\ \mathrm{km/h}$$ for $$2.5\ \mathrm{h}. $$How far does she travel?

Accepted Answer

$$45,000\ \mathrm{m}$$

Question 6

A car travels $$100.0\ \mathrm{km} at$$ $$50.0\ \mathrm{km/h}$$, then another $$100.0\ \mathrm{km} at$$ $$100.0\ \mathrm{km/h}. $$What is the average speed for the entire $$200.0\ \mathrm{km}$$ trip?

Accepted Answer

$$66.7\ \mathrm{km/h}$$

Question 7

Which equation gives the average velocity $$v_{av}$$ for displacement $$\Delta x$$ over time interval $$\Delta t$$?

Accepted Answer

$$v_{av} = \dfrac{\Delta x}{\Delta t}$$

Question 8

If the position of a particle is given by $$x(t) = (2.10\ \mathrm{m/s^2$})t^2$ + 2.80\ \mathrm{m}$$, what is its instantaneous velocity at $$t = 5.00\ \mathrm{s}$$?

Accepted Answer

$$v = 21.0\ \mathrm{m/s}$$

Question 9

A car accelerates from rest to $$90\ \mathrm{km/h} in$$ $$5.0\ \mathrm{s}. $$What is the magnitude of its average acceleration in $$\mathrm{m/s^2$}$$?

Accepted Answer

$$5.0\ \mathrm{m/s^2$}$$

Question 10

Which of the following is true about acceleration and velocity?

Accepted Answer

An object can have zero velocity but nonzero acceleration, such as at the top of its trajectory when thrown upward.

Question 11

A ball is dropped from rest from a cliff. What is its speed after $$2.00\ \mathrm{s}$$? (Assume $$g = 9.8\ \mathrm{m/s^2$}$$ and ignore air resistance.)

Accepted Answer

$$v = 19.6\ \mathrm{m/s}$$

Question 12

A ball is thrown upward with an initial velocity of $$15.0\ \mathrm{m/s}. $$What is the maximum height it reaches? (Use $$g = 9.8\ \mathrm{m/s^2$})$$

Accepted Answer

$$h = 11.5\ \mathrm{m}$$

Question 13

A ball is thrown upward with $$v_0 = 15.0$$\ \mathrm{m/s}$$. How long does it take to reach its maximum height?

Accepted Answer

$$t = 1.53\ \mathrm{s}$$

Question 14

A ball is thrown upward and returns to the thrower's hand. What is its velocity when it returns?

Accepted Answer

$$v = -15.0\ \mathrm{m/s}$$

Question 15

A ball is thrown upward from the edge of a $$50.0\ \mathrm{m}$$ cliff with $$v_0 = 15.0$$\ \mathrm{m/s}$$. How long does it take to reach the base of the cliff? (Use g = 9.8$$\ \mathrm{$$m/s^2$$}$$)

Accepted Answer

$$t = 5.07\ \mathrm{s}$$

Question 16

Which kinematic equation is used to find the final velocity $$v of an $$object under constant acceleration $$a$$ after displacement $$\Delta x$$?

Accepted Answer

$$v^2$$ = $$v_0^2 + 2 a$$ \Delta x$$

Question 17

A car accelerates from rest at $$2.00\ \mathrm{m/s^2$}$$ along a $$150.0\ \mathrm{m}$$ runway. What is its final speed at the end of the runway?

Accepted Answer

$$v = 24.5\ \mathrm{m/s}$$

Question 18

Which of the following best describes the acceleration due to gravity near Earth's surface?

Accepted Answer

It is always negative, directed downward, with magnitude $$9.8\ \mathrm{m/s^2$}.$$

Motion in One Dimension (Kinematics) – Study Notes

Guida di studio - Domande di pratica

Study guide - Flashcard