<span>Products that customers consider essentials or necessities tend to have less elasticity than products viewed as luxury or discretionary. If a customer believes he needs a certain product for survival, quality of life, or pleasure, he is more likely to stretch a bit to purchase the item if the price goes up. On the contrary, a product viewed as optional is a less likely purchase as the price increases because the customer believes he can live without it.Customer OptionsThe more options a customer has to meet a particular functional or emotional need, the more elastic a product's demand. This is why a company with a monopoly has a huge advantage. Customers don't have options and feel compelled to buy from the given provider. In highly competitive industries, price differentials are usually less among competing brands because of the ability customers have to select lower-priced alternatives. A closely related factor is the cost of switching brands. Cell phone customers often wait to change providers to avoid penalties if they are obligated to service contracts. </span><span />
In simple words, the work done by all the parties is actually same. This case could be understood by using the theories of potential energy. The work performed should be measured as equivalent as the work done is equal to the increase in gravitational energy potential and is the same with all cases as the possible change in energy based on truck height or elevation and regardless of direction.
