Exercises physics and chemistry 3 and 4 ESO

Do the exercises and send the answer to the teacher with "Formulario de contacto"

1) In an experiment, we determine the density of an object by measuring its mass and its volume. The results are:

Mass (g): 23,7; 23,5;  23,4;  23,6

Volume (cm3): 3,3;  3,2;  3,1;  3,2

Determine with the absolute and the relative eroors, the mean values for the mass and the volume and the final result for the density. Could this material be gold (d=19,6g/cm3)

2) When we measure the duration (T) of a journey against speed (V: km/h), we get these values:

v(km/h)    T(h)

120          2

100          2. 4

80            3 

60            4

40            8

Graph the time(y) against speed. Determine the equation which relates time and speed (time as a function of speed) and the travelled distance. Check your equation is dimensionally rigth