3) Se sabe que la aceleración (a) se define como el cambio de la velocidad \( (v) \) en el tiempo (t), entonces \( a=\frac{d}{d t} v \), si la velocidad en cierto sistema está determinada por: \( v(t)=t^{2}-5 t \) a) ¿Cuál será el tiempo en el cual la velocidad es constante? \( v(t)=-S \)

A child pulls a wagon with a force of 16 pounds. The handle of the wagon makes an angle of \( 60^{\circ} \) with the ground. Express the force vector \( F \) in terms of \( i \) and \( j \). \( F=(\square) i+(\square j \) (Simplify your answer, including any radicals. Use integers or fractions for any numbers in the expression.)

Quesito 2D Una stecca colpisce una palla da biliardo di 250 g , inizialmente ferma, esercitando una forza media di 80 N per un tempo di 8 ms . Con quale velocita parte la palla dopo l'urto? Quesito 3D Un uotno spara in orizzontala

52. A certain planet has a mass of \( 3.3 \times 10^{23} \mathrm{~kg} \) and a adjus of \( 2.6 \times 10^{6} \mathrm{~m} \). What is the acceleration due to gravity on the surface of this planet? a. \( 0.54 \mathrm{~m} / \mathrm{s}^{2} \) b. \( 3.3 \mathrm{~m} / \mathrm{s}^{2} \) c. \( 4.0 \mathrm{~m} / \mathrm{s}^{2} \) d. \( 9.8 \mathrm{~m} / \mathrm{s}^{2} \)

travel at without slipping? A car travels at a constant speed in a circular path of 120 m radius. It completes one circuit in 23 s . If the ground is level, what is the minimum coefficient of friction between the tires and the road?

The brightness of a light bulb changes inversely with resistance and directly with voltage. What is the new resistance if a 60 -watt, 120 -volt bulb is used in place of a 100 -watt, 120 -volt bulb with 144 ohms?