1) A mass of 60kg of water is heated by 80oC. How much energy is required to do this? Water has a specific heat capacity of 4200 J/kg°C.

2) Aluminium has a specific heat capacity of 900 J/kg°C and water has a specific
heat capacity of 4200 J/kg°C. Based on these figures, which of the following
statements is true?

a) Water will turn to steam more easily than aluminium metal will melt.

b) 1kg of aluminium will take much longer to change its temperature than water

c) Aluminium is much more suitable for use in car radiators than water

d) 1kg of water needs to receive much more energy than 1kg of aluminium to change its temperature by 1°C

Consider a uniformly charged ring in the xy plane, centered at the origin. the ring has radius a and positive charge qdistributed evenly along its circumference. a)what is the direction of the electric field at any point on the z axis? . b)what is the magnitude of the electric field along the positive z axis? use k in your answer, where k=14πϵ0. d)the ball will oscillate along the z axis between z=d and z=−d in simple harmonic motion. what will be the angular frequency ω of these oscillations? use the approximation d≪a to simplify your calculation; that is, assume that d2+a2≈a2. express your answer in terms of given charges, dimensions, and constants