Its very simple if a body is moving in circle the magnitude of its velocity remain constant but its direction changes because velocity is directed towards tangent and at every point in a cirlce its direction will be different (along tangent) so velocity is not uniform .As acceleration is the rate change of velocity so it will be non zero because velocity is changing due to its direction.
Use the equation q=mc/\T, where q is the heat lost, m is mass, and /\T is the change in temperature, and c is the specific heat.
q=50kg(3470J/kg K)(2K)
q=<span>347000 J
Any other questions, just ask.
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False
Because you can see using a thermal camera I guess