repaso examen no. 1 física 215 profesor: santander nieto...

Repaso Examen No. 1

Física 215

Profesor: Santander Nieto Ramos, Ms. PhD.

Nota aclaratoria:

Esto es solo un repaso de algunos temas que se van a

evaluar en el examen No. 1 de curso Física 215, los

ejercicios planteados aquí no serán los mismos del

examen como tal.

1. You drop a rock off a bridge. When the rock has fallen 4 m,

you drop a second rock. As the two rocks continue to fall, what

happens to their velocities?

A) Both increase at the same rate?

B) The velocities of the first rock increases faster than the velocity of the second.

C) The velocity of the second rock increases faster than the velocity of the first.

D) Both velocities stay constant.





2. A ball thrown straight up. What are the velocity and acceleration of the

ball at the highest point in its path?

A) v = 0, a = 0

B) v = 0, a= 9.8 m/s2 up.

C) v = 0, a = 9.8 m/s2 down.

D) v = 9.8 m/s up, a = 0

E) v = 9.8 m/s down, a = 0.

A) v = 0, a = 0

B) v = 0, a= 9.8 m/s2 up.

C) v = 0, a = 9.8 m/s2 down.

D) v = 9.8 m/s up, a = 0

E) v = 9.8 m/s down, a = 0.

3. Which of the following five coordinate versus time graphs

represents the motion of an object moving with a constant speed?

A) A

B) B

C) C

D) D

E) E

A) A

B) B

C) C

D) D

E) E

4. You drive 4km at 30 km/h and then another 4 km at 50 km/h.

What is your average speed for the whole 8- km trip?

A) More than 40 km/h

B) Equal to 40 km/h

C) Less than 40 km/h

D) Not enough information


B) Equal to 40 km/h



5. A ball is dropped from the top of a tall building. At the same

instant, a second ball is thrown upward from the ground level.

When the two balls pass one another, one on the way up, the other

on the way down, compare the magnitudes of their acceleration:

A) The acceleration of the dropped ball is greater

B) The acceleration of the ball thrown upward is greater

C) The acceleration of both balls is the same,

D) The acceleration changes during the motion, so you cannot predict

the exact value when the two balls pass each other.

E) The acceleration are in opposite directions.







6. A ball is thrown downward at a speed of 20 m/s. Choosing the +y

axis pointing up and neglecting air resistance, which equation(s)

could be used to solve for other variables? The acceleration due to

gravity is g = 9.8 m/s2 downward.

A) v = (20 m/s) –gt

B) y = y0 + (-20 m/s)t – (1/2)gt2.

C) v2 = (20 m/s)2 – 2g(y-y0)).

D) (20 m/s) = (v + v0)/2.

E) All of the above.

A) v = (20 m/s) –gt

B) y = y0 + (-20 m/s)t – (1/2)gt2.

C) v2 = (20 m/s)2 – 2g(y-y0)).

D) (20 m/s) = (v + v0)/2.


7. Which of the three kicks in figure is in the air for the longest time?

They all reach the same maximum height h.

Ignore air resistance.

A)

B)

C)

D) all the same time

A)

B)

C)


8. A baseball is hit high and far. Which of the following statements is true?

At the highest point,

A) the magnitude of the acceleration is zero.

B) the magnitude of the velocity is zero

C) the magnitude of the velocity is the slowest.

D) more than one of the above is true.

E) none of the above are true.






9. Which statements are not valid for a projectile? Take up as positive.

A) The projectile has the same x velocity at any point on its path.

B) The acceleration of the projectile is positive and decreasing

when the projectile is moving upwards, zero at the top, and

increasingly negative as the projectile descends.

C) The acceleration of the projectile is a constant negative value.

D) The y component of the velocity of the projectile is zero at the

highest point of the projectile’s path.

E) The y velocity at the highest point is zero.








E) The y velocity at the highest point is zero.

10. Which of the following five acceleration versus time graphs is

correct for an object moving in a straight line at a constant velocity of

20 m/s?

A) I

B) II

C) III

D) IV

E) V

A) I

B) II

C) III

D) IV

E) V

11. A car accelerates from rest on a straight road. A short time later,

the car decelerates to a stop and then returns to its original position

in a similar manner, by speeding up and then slowing to a stop.

Which of the following five coordinate versus time graphs best

describes the motion?

A) I

B) II

C) III

D) IV

E) V

A) I

B) II

C) III

D) IV

E) V


represents the motion of an object whose speed is increasing?

A) I

B) II

C) III

D) IV

E) V

A) I

B) II

C) III

D) IV

E) V

13. Consider the following five graphs (note the axes carefully). Which

of these represent(s) motion at constant speed?

A) IV only

B) IV and V only

C) I, II, and III only

D) I and II only

E) I and IV only

A) IV only

B) IV and V only


D) I and II only

E) I and IV only

14. An object is dropped from rest. Which of the five following

graphs correctly represents its motion? The positive direction is

taken to be downward.

A) I

B) II

C) III

D) IV

E) V

A) I

B) II

C) III

D) IV

E) V

15. A stone is dropped from a cliff. The graph (carefully note the axes)

that best represents its motion while it falls is:

A) I

B) II

C) III

D) IV

E) V

A) I

B) II

C) III

D) IV

E) V

16. An object is thrown vertically into the air. Which of the following

five graphs represents the velocity (v) of the object as a function of the

time (t)? The positive direction is taken to be upward

A) I

B) II

C) III

D) IV

E) V

A) I

B) II

C) III

D) IV

E) V

Repaso Examen No. 1

Física 215

Profesor: Santander Nieto Ramos, Ms. PhD.

Nota aclaratoria:

Esto es solo un repaso de algunos temas que se van a

evaluar en el examen No. 1 de curso Física 215, los

ejercicios planteados aquí no serán los mismos del

examen como tal.

1. You drop a rock off a bridge. When the rock has fallen 4 m,

you drop a second rock. As the two rocks continue to fall, what

happens to their velocities?









2. A ball thrown straight up. What are the velocity and acceleration of the

ball at the highest point in its path?

A) v = 0, a = 0

B) v = 0, a= 9.8 m/s2 up.

C) v = 0, a = 9.8 m/s2 down.

D) v = 9.8 m/s up, a = 0

E) v = 9.8 m/s down, a = 0.

A) v = 0, a = 0

B) v = 0, a= 9.8 m/s2 up.

C) v = 0, a = 9.8 m/s2 down.

D) v = 9.8 m/s up, a = 0

E) v = 9.8 m/s down, a = 0.


represents the motion of an object moving with a constant speed?

A) A

B) B

C) C

D) D

E) E

A) A

B) B

C) C

D) D

E) E

4. You drive 4km at 30 km/h and then another 4 km at 50 km/h.

What is your average speed for the whole 8- km trip?


B) Equal to 40 km/h




B) Equal to 40 km/h



5. A ball is dropped from the top of a tall building. At the same

instant, a second ball is thrown upward from the ground level.

When the two balls pass one another, one on the way up, the other

on the way down, compare the magnitudes of their acceleration:













6. A ball is thrown downward at a speed of 20 m/s. Choosing the +y

axis pointing up and neglecting air resistance, which equation(s)

could be used to solve for other variables? The acceleration due to

gravity is g = 9.8 m/s2 downward.

A) v = (20 m/s) –gt

B) y = y0 + (-20 m/s)t – (1/2)gt2.

C) v2 = (20 m/s)2 – 2g(y-y0)).

D) (20 m/s) = (v + v0)/2.


A) v = (20 m/s) –gt

B) y = y0 + (-20 m/s)t – (1/2)gt2.

C) v2 = (20 m/s)2 – 2g(y-y0)).

D) (20 m/s) = (v + v0)/2.


7. Which of the three kicks in figure is in the air for the longest time?

They all reach the same maximum height h.

Ignore air resistance.

A)

B)

C)


A)

B)

C)


8. A baseball is hit high and far. Which of the following statements is true?

At the highest point,











9. Which statements are not valid for a projectile? Take up as positive.








E) The velocity at the highest point is zero.








E) The velocity at the highest point is zero.