Someone please help me

The of a machine determines its "usefulness." a. input force b. output force c. mechanical advantage

Part a constants huck finn walks at a speed of 0.60 m/s across his raft (that is, he walks perpendicular to the raft's motion what is huck's velocity (speed and direction) relative to the river bank? express your answer to three significant figures and include the appropriate units. relative to the shore)

How will the system respond to a temperature increase?