## Chemistry: A Molecular Approach (3rd Edition)

$N=\frac{kg\times m}{s^{2}}$ kN and pN are the most suitable.
1. $F= m\times a= \frac{m\times V}{t}=\frac{m\times l}{t^{2}}$ SI base units that force consists of are length -(m); time -(s); mass - (kg) 2. We convert speed from mph to m/s using conversion: $1 mile = 1.6093km$ $1km=1000m$ $1h=3600s$, then $85.5115 km/h = 88511.5 m/h = 24.5865 m/s$ 3. Calculate force: $F = \frac{10,000kg \times 24.5865 m/s}{1s}=245,865 N =245.865$ $kN$ 4. Calculate next force without conversion: $F = \frac{10^{-20} kg \times 3 \times 10^{8} m/s}{1s}=3 \times 10^{-12} N =3$ $pN$