ue cantidad de calor se debe aplicar a una barra de oro de 24 kg para que eleve su tempera \( 45^{\circ} \mathrm{C} \) a \( 90^{\circ} \mathrm{C} \).(calor específico del oro: \( 129 \mathrm{~J} / \mathrm{Kg} \cdot{ }^{\circ} \mathrm{C} \) )

3) Choose the correct alternative and rewrite the statement (i) The weight of a body on the earth's surface \( =\ldots \ldots . \). \( \begin{array}{llll}\text { (a) } \frac{G M m}{R} & \text { (b) } \frac{G M m}{R^{2}} & \text { (c) } G M m R^{2} & \text { (d) } \frac{G m}{R^{2}}\end{array} \)

A coil with an area of \( 0.6 \mathrm{~m}^{2} \) is held with its axis coinciding with the direction of a magnetic field (surface perpendicular to magnetic field), with a strength of 0.4 T . 8.3 Calculate the magnetic flux.

8.4 To produce an emf of 9 V , the area of the coil, with its axis coinciding with the direction of a magnetic field (area perpendicular to magnetic field), is halved in 2 minutes from \( 0.6 \mathrm{~m}^{2} \) to \( 0,3 \mathrm{~m}^{2} \). Calculate the number of turns around the coil.

3. Si un ratón y un elefante comen ambos con la misma energía cinética, ¿podrías decir cuál corre más aprisa? Explica tu respuesta en términos de la ecuación de la ECT?

An object of mars 5.0 kg moves around a aincle of radius 6.0 m coith a constant speeds of 10 . om/s. Calc-te 1 . angular velocity Centripetal force on the body