What part of the hammer acts as the fulcrum when the hammer is used to remove a nail

1700 j of energy is lost from 0.14 kg object , the temperature decreases from 50°c to 45°c what is the specific heat of this object, amd what is the material ?

Aspring that is stretched 2.6 cm stores a potential energy of 0.053 j. what is the spring constant of this spring?

Suppose that the half-life of an element is 1000 years. how many half-lives will it take before one-eighth of the original sample remains? 8 125 12.5 3