Quick answer: Uniform circular motion is travel at constant speed along a circle. This AP Physics 1 test on centripetal acceleration has 8 questions worth 20 marks, to do in 40 minutes: arrows at one point, control-line aircraft and a heavier, bigger planet. The mark scheme is on a separate page; free printable PDF.
This test covers circular motion and gravitation at AP Physics 1 level. Use g = 9.81 m/s² and G = 6.67 × 10⁻¹¹ N m²/kg². Show all working for calculations and use full sentences in the written parts. Calculators are allowed.
Level: AP Physics 1 (algebra-based) · Curriculum: AP P1 Unit 2
Question 1 Arrows at one point (2 marks)
The figure shows a puck at P. Choose from A, B, C or D.- Which arrow shows the direction of the velocity? (1 mark)
- Which arrow shows the direction of the acceleration? (1 mark)
Question 2 Control-line aircraft (3 marks)
A model aircraft of mass 0.50 kg flies in a horizontal circle of radius 8.0 m on a control line, taking 2.5 s per lap.- Calculate its speed. (1 mark)
- Calculate its centripetal acceleration. (1 mark)
- Calculate the tension in the line, ignoring the weight. (1 mark)
Question 3 A heavier, bigger planet (2 marks)
Planet X has four times the mass of the Earth and twice its radius.- Calculate gX / gEarth. (1 mark)
- Calculate the weight of a 60 kg student on planet X, using g = 9.81 N/kg for the Earth. (1 mark)
Question 4 Titan around Saturn (3 marks)
Titan orbits Saturn (mass 5.68 × 10²⁶ kg) at a radius of 1.22 × 10⁹ m. Use G = 6.67 × 10⁻¹¹ N m²/kg².- Calculate its orbital speed. (2 marks)
- Calculate its period in days. (1 mark)
Question 5 Vertical circle (3 marks)
A 0.30 kg ball on a string of length 0.80 m moves in a vertical circle. Use g = 9.81 m/s².- State Newton’s second law along the line to the centre at the top. (1 mark)
- Calculate the tension at the top when the speed is 4.0 m/s. (1 mark)
- Calculate the tension at the bottom when the speed is 5.0 m/s. (1 mark)
Question 6 Outward force argument (3 marks)
A student writes: “The Moon does not fall into the Earth because the Earth’s gravity is balanced by an outward force.” Write a paragraph that evaluates this claim, using forces and acceleration.Question 7 Two orbits compared (2 marks)
Satellite B orbits at twice the radius of satellite A around the same planet.- Calculate vB / vA. (1 mark)
- Calculate TB / TA. (1 mark)
Question 8 Linear graph (2 marks)
A student measures the tension F for several periods T of a bung of mass m on radius r. State which quantities should be plotted to give a straight line, and what the gradient equals. Justify using the equation of motion.
