How much force is needed to accelerate a 3kg skateboard at 5 m/s2

Acube has a volume of 2011 cubic inches. what is the angle measure between a side of a cube and its interior diagonal?

An initially unpolarized light if intensity 500 w/m^2 passes through four polarizers. the transmission axis between adjacent polarizers is 45∘. what percentage of the initial intensity is transmitted by the system?

Determine the age of a fossil if it had only one eighth of its original carbon-14 content remaining?