The mass of a rectangular block of wood is 40.0 g. It measures 4.0 cm x 2.0 cm x 4.0 cm. The numerical answer for the density round to the correct significant figures is g/cm^3

Can you guys me with question no. 5!

Which real-world scenarios below represent physical and chemical changes? -running a car -exploding fireworks -mixing water and powdered drink mix -combining oil and vinegar to make salad dressing -taking aspirin for a headache -diluting bleach with water-digesting dinner-spreading peanut butter on bread

Arollercoaster car at the top of a hill has potential energy kinetic energy chemical energy light energy