a )John heats up 2kg of water from 20 degrees c to 80 degrees c. How much energy input did this require? b )When John weighs the water at the end, he has less than he started with. Why might this be? c) What hazards are in this experiment?
a) energy transferred = mass.specific heat capacity.temperature change, or E = m.c.theta. c is provided at 4181 joules per kg. so E = 2.4181.(80-20) = 501720 joules
b) some water has evaporated off as it was heated
c) 80 degree water can burn, care should be taken
RH
Related Physics GCSE answers
All answers ▸Can you explain the difference between distance and displacement
A bat emits a sound wave with a frequency of 25.0 kHz and a wavelength of 0.0136 metres. Calculate the speed of this sound wave.
Sound waves are longitudinal. Describe a longitudinal sound wave?
A car of mass 1000 kg is travelling at 20 (m/s). The car crashes into a tree, and comes to a complete halt in 0.05s. Calculate the force acting on the car during the collision.