How do you convert 1.3*10^6cal into joules

There are weak or strong attractive forces between atoms of liquids with a high viscosity

Determine el momento angular de un rueda de 3000g moviendose a 10m/s con un radio de giro de 400cm

In a simplified model of the human eye, the aqueous and vitreous humors and the lens all have a refractive index of 1.40, and all the refraction occurs at the cornea, whose vertex is 2.60 cm from the retina. what should be the radius of curvature of the cornea such that the image of an object 40.0 cm from the cornea’s vertex is focused on the retina?