Exam-style multiple choice and written questions with full markschemes. Check multiple choice answers straight away, or type, photograph or draw a written answer and get it marked.
An electric winch raises a crate vertically at constant speed. Figure 1 shows the power transfers while the winch is operating.
State the energy form supplied to the winch and the useful energy form gained by the crate.
Calculate the efficiency of the winch.
Calculate the useful energy transferred to the crate in 25 s at the operating conditions shown.
A constant force of magnitude acts on a box, directed north of east. The box moves east and then north. What is the total work done by the force on the box?
Answer: D. Work on each segment is the force component along that segment multiplied by its length. The east and north components are and Thus which is to two significant figures. A: subtracts the northward contribution instead of adding it, giving B: includes only the work during the northward displacement, C: includes only the work during the eastward displacement, Remember: add the work contributions from successive displacements, including their signs.
Unlock every question in this topic, then type, photograph or draw your answer and have it marked against the markscheme. Find out where you are dropping marks.