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? \( v(t)=-S \)

Cognome, classe, data Quesito 1A Un sistema è composto da due sfere a contatto su un piano orizzontale. Sfera 1: sfera omogenea di raggio 2 cm e massa 3 kg . Sfera 2: sfera omogenea di raggio 4 cm e massa 6 kg . Calcolare le coordinate del centro di massa.

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?

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. \( 9.8 \mathrm{~m} / \mathrm{s}^{2} \)

ON 1: KINEMATICS A ship that can cruise at \( 48 \mathrm{~km} / \mathrm{h} \) in still waters sets course due south-west. It is driven off course by a current flowing West \( 26^{\circ} \) North at a velocity of \( 8 \mathrm{~km} / \mathrm{h} \). Calculate the following: \( 1.1 .1 \quad \) The resultant velocity in magnitude and direction \( 1.2 \quad \) The distance the ship will cruise in 5 hours

A bullet is fired at an angle of \( 30^{\circ} \) to the horizontal at a velocity of \( 400 \mathrm{~m} / \mathrm{s} \) Calculate the following: 1.2 .1 The maximum height reached by the bullet 1.2 .2 The horizontal displacement when the bullet hits the ground