Emily is pushing a toy sand truck. She realizes it is much harder to push the truck when it is full of sand than when it is empty. What is the reason for this?
An object pushed with a greater force has less mass.
An object with a greater mass requires a smaller force to accelerate.
An object with a greater mass requires a greater force to accelerate.
An object pushed with a greater force has a greater mass.

It is reasonable to assume that the bulk modulus of blood is about the same as that of water (2.2 gpa). as one goes deeper and deeper in the ocean, the pressure increases by 10000 pa for every meter below the surface. if a diver goes down 80.0 m in the ocean, by how much does each cubic centimeter of her blood change in volume? give the answer in cubic centimeters (actually one cubic centimeter equals one milliliter).