Answer:
( About ) 1,099 pounds
Step-by-step explanation:
The force required to keep this truck from rolling down the hill is opposed by the force of friction, comparative to the 2600 pounds of force against this friction. It should be that this opposing force is at work more towards the bottom of this hill, and thus the question asks the magnitude of latter force to keep this truck idle -
|| F || = sin( 25 ) * ( Fg ) = sin( 25 ) * ( 2600 lb ) = ( About ) 1098.80748 pounds
This can be rounded to a solution of 1099 pounds