Two blocks of aluminum (specific heat c=0.22 cal/g celsius) with masses of 1000 g and 100 g are at a temperature of 70 c. which block has more thermal (internal) energy? explain why?

Internal thermal energy is given as

so it will depend on the product of mass, specific heat capacity and temperature.

so here we know that both blocks are identical with same initial temperature

So the block with larger mass must have more internal energy

So here the correct answer would be the block with mass 1000g

block with mass 1000 g must have more internal energy

diagram is missing, but i will try to explain your doubt.

answer:

amplitude is the maximum displacement or distance moved on a point of a vibrating body or wave measured from its equilibrium position.it is equal to half the length of vibration path.