Step-by-Step Solution
Given Information
We need to find the weight of an object that has given mass
The Weight can be found by product of mass and gravitational acceleration $g = 9.81\,\,{\rm{m/}}{{\rm{s}}^{\rm{2}}}$
Step-1: Part (a)
Mass =8 kg
Weight
\[\begin{array}{l} W = mg\\ \\ W = \left( {8\,\,{\rm{kg}}} \right)\left( {9.81\,\,{\rm{m/}}{{\rm{s}}^{\rm{2}}}} \right)\\ \\ W = 78.5\,\,{\rm{N}} \end{array}\]
Step-2: Part (b)
Mass =0.04 kg
Weight
\[\begin{array}{l} W = mg\\ \\ W = \left( {0.04\,\,{\rm{kg}}} \right)\left( {9.81\,\,{\rm{m/}}{{\rm{s}}^{\rm{2}}}} \right)\\ \\ W = 0.3924\,\,{\rm{N}} \end{array}\]
Step-3: Part (c)
Mass = 760 Mg
Weight
\[\begin{array}{l} W = mg\\ \\ W = \left( {760 \times {{10}^3}\,\,{\rm{kg}}} \right)\left( {9.81\,\,{\rm{m/}}{{\rm{s}}^{\rm{2}}}} \right)\\ \\ W = 7.46 \times {10^6}\,\,{\rm{N}}\\ \\ W = 7.46\,\,{\rm{MN}} \end{array}\]