If all of the following objects have the same velocity, which one has the greatest momentum? A. a pencil
B. a semi truck
C. a sofa
D. a text book

Zeros that follow non-zeros numbers and are also to the right of a decimal point are significant

Arod of some material 0.20 m long elongates 0.20 mm on heating from 21 to 120°c. determine the value of the linear coefficient of thermal expansion [in (degrees c)^-1] for this material.

Astone weighing 1.5 kilograms is resting on a rock at a height of 20 meters above the ground. the stone rolls down 10 meters and comes to rest on a patch of moss. the gravitational potential energy of the stone on the moss is joules.