Starting from rest, a 2 kg block of wood slides a distance of two meters down a friction-less slope, as shown. What is the approximate kinetic energy of the wooden block at the bottom of the slope?

3.1 A truck with a mass of 1 ton is moving at \( 80 \mathrm{~km} / \mathrm{h} \) on a horizontal plane and braked to rest over 40 m . Calculate the following: 3.1.1 The deceleration 3.1.2 The braking force

Find the dimension of gravitational cons tant and pressure

4) Dos puntos, A y B, están en la misma horizontal separados por una distancia de 400 m . Desde A parte del reposo y hacia B un movil con una aceleración de \( 1,8 \mathrm{~m} / \mathrm{seg} \). S.multaneamente y desde B, parte hacia A otro movil con una rapidez inicial de \( 4 \mathrm{~m} / \mathrm{seg} \) y una aceleración de \( 2,8 \mathrm{~m} / \mathrm{seg}{ }^{2} \). Calcular donde y cuando se encuentran.

A car with a mass of 800 kg accelerates uniformly from rest to \( 100 \mathrm{~km} / \mathrm{h} \) for 8 seconds up an incline that makes an angle of \( 30^{\circ} \) with the horizontal. The frictional resistance is 280 N . Calculate: 3.2.1 The work done against the frictional force when the velocity reaches \( 100 \mathrm{~km} / \mathrm{h} \) \( \begin{array}{l}\text { The work done against the gravitational component parallel to } \\ \text { 3.2.2 the plane }\end{array} \)

9. A 0.13 kg puck is moving in a circular path on a horizontal air table where friction is negligible. The centripetal force is provided by a cord 0.68 m long attached in the centre of the air table. If the tension in the cord is 2.5 N , what is the speed of the puck?