Una persona hala de su maleta de 28 Kg , a lo latgo de un plano horizonlal mediante una cuerda que forma un ángulo do \( 35^{\circ} \) con la horizontalaplicando una fuerza de 100 N la maleta parte del reposo \( y \) ol coeficiente de rozamiento entre el piso y la maleta es 0,15 ¿Cuánto trabajo realiza la persona en 9 s ? Seleccione una: a. \( W=9721 \mathrm{~J} \) b. \( W=3815,4 \) c. \( W=648,8 \mathrm{~J} \) d. \( W=5839,3 \mathrm{~J} \) e. \( W=7128 \mathrm{~J} \) e.

(b.) student : (1) My Day 9. An airplane starts from rest and accelerates at a constant rate of \( 3.00 \mathrm{~m} / \mathrm{s}^{2} \) for 30.0 s before leaving the ground. a. How far did it move? b. How fast was it going when it took off? 10. A brick is dropped from a high scaffold. a. What is its velocity after 4.0 s ? b. How far does the brick fall during this time? 11. A tennis ball is thrown straight up with an initial speed of \( 22.5 \mathrm{~m} / \mathrm{s} \). It is caught at the same distance above the ground. a. How high does the ball rise? b. How long does the ball remain in the air?

\( b= \) Expresar 40 kgf en N

28.11. Un alambre largo y recto está a lo largo del eje \( z \) y conduce \( u \) corriente de 4.00 A en la dirección \( +z \). Determine el campo magnétic (magnitud y dirección) producido en los siguientes puntos por un seg mento de 0.500 mm del alambre con centro en el origen: a) \( x=2.00 \mathrm{~m} \), \( \begin{array}{l}y=0, z=0 ; b) x=0, y=2.00 \mathrm{~m}, z=0 \\ 2.00 \mathrm{~m}, z=0 ; d) x=0, y=0, z=2.00 \mathrm{~m} \text {. }\end{array} \)

20. Assuming equal rates of uniform acceleration in both cases, how much further would you travel if braking from \( 56 \mathrm{~m} / \mathrm{s} \) to rest than from \( 28 \mathrm{~m} / \mathrm{s} \) ? \( \begin{array}{llll}\text { A) } 4 \text { times farther } & \text { B) } 3.2 \text { times farther } & \text { C) } 4.8 \text { times farther } & \text { D) } 5.2 \text { times farther } \\ \text { 21. An object is moving in a straight line with constant acceleration. Initially it is traveling at } 16 \mathrm{~m} / \mathrm{s} .\end{array} \) \( \begin{array}{llll}\text { Three seconds later it is traveling at } 10 \mathrm{~m} / \mathrm{s} \text {. How far does it move during this time? } \\ \begin{array}{llll}\text { () } 30 \mathrm{~m} & \text { B) } 39 \mathrm{~m} & \text { C) } 48 \mathrm{~m} & \text { D) } 57 \mathrm{~m}\end{array}\end{array} \).

22. An object is moving with constant non-zero acceleration in the \( +x \) direction. The position versus time graph of this object is \( \begin{array}{ll}\text { A) a horizontal straight line. } & \text { B) a vertical straight line. } \\ \text { C) a straight line making an angle with the time axis. } & \text { D) a parabolic curve. } \\ \text { 23. An object is moving with constant non-zero acceleration in the }+x \text { direction. The velocity versus } \\ \text { time graph of this object is } & \text { B) a vertical straight line. } \\ \begin{array}{ll}\text { A) a horizontal straight line. } & \text { D) a parabolic curve. }\end{array}\end{array} \).