Physics 9702 · AS & A Level · Kinematics of uniform circular motion
Kinematics of uniform circular motion — practice question
Model the Earth as a sphere of uniform size with radius $6.37 \times 10^6\,\text{m}$. Cambridge is located on the Earth's surface at latitude $52.2^\circ$ north of the Equator, as illustrated in Fig. 1.1. As the Earth rotates about its axis, Cambridge follows a circle parallel to the Equator, but with a smaller radius.
(a(i))[1]
Show that the radius of the circle Cambridge moves around is $3.90 \times 10^6\,\text{m}$.
(a(ii))[3]
Calculate the speed at which Cambridge travels around the circle.
(b(i))[2]
A student of mass $58.6\,\text{kg}$ is standing on horizontal ground in Cambridge. Determine the magnitude of the resultant force that acts to produce the student's circular motion.
(b(ii))[1]
On Fig. 1.2, draw an arrow to show the direction of the resultant force acting on the student.
(b(iii))[2]
On Fig. 1.3, draw labelled arrows starting from the student to show the directions of the forces acting on the student that produce the resultant force in (b)(ii).
Worked solution & mark scheme
This 9-mark question has a full step-by-step worked solution and mark scheme. One marking point: “The calculation gives $6.37\times10^6\times\cos52.2^\circ$, so the radius is $3.90\times10^6\,\text{m}$” …