Physics 5054 · O Level · Turning effect of forces

Turning effect of forces — practice question

Fig. 2.1 shows a student carrying out a press-up. An upward total force $F$ acts on his hands, and an upward force also acts on his toes. The student’s weight is 600 N, and this force acts downward through his centre of mass.
(a(i))[1]

Explain why work is done by the student as his body rises from the ground.

(a(ii))[1]

State the type of energy that the student uses to do this work.

(b(i))[1]

At the point shown in Fig. 2.1, the student is at rest. The student’s weight produces a moment about his toes. Calculate the moment of the weight of the student about his toes.

(b(ii))[2]

Calculate the magnitude of the force $F$.

Worked solution & mark scheme

This 5-mark question has a full step-by-step worked solution and mark scheme. One marking point: A force acts through a distance in the same direction

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