Consider a 0.63-kg sample of metal at room temperature of 20
c. the addition of 642,000 j increases its temperature to its melting point (782
c. an additional 59,400 j causes the sample to completely liquefy. what is the heat of fusion of the sample?

If forces acting on an object are unbalanced, which factors may result fron an unbalanced force? check all that apply

Aplane travels 1000 miles in 5 hours .what is the planes average speed?

Three different objects, all with different masses, are initially at rest at the bottom of a set of steps. each step is of uniform height . the mass of each object is a multiple of the base mass : object 1 has mass 4..00m , object 2 has mass 1..96m , and object 3 has mass . when the objects are at the bottom of the steps, define the total gravitational potential energy of the three-object system to be zero. if the objects are then relocated as shown, what is the new total potential energy of the system? each answer requires the numerical coefficient to an algebraic expression. each algebraic expression is given using some combination of the variables , , and , where is the acceleration due to gravity. enter only the numerical coefficient. (example: if the answer is 1..23mgd , just enter 1.23)