CAIE IGCSE Physics 1.5.1.4 An Object Either Remains At Rest or Questions
Practise explaining why zero resultant force means no acceleration, how balanced driving and resistive forces produce constant speed, and how force evidence determines motion.
Syllabus
2026–2028
Course
Physics 0625
Exam points
State that zero resultant force means no acceleration and explain constant-speed motion when driving and resistive forces balance.
CAIE IGCSE Physics 1.5.1.4 An Object Either Remains At Rest or Questions question 1
[Maximum number: 2]
Fig. 1.1 shows a straight section of a river where the water is flowing from right to left at a speed of 0.54m/s.
Fig. 1.1 (not to scale)
A swimmer starts at point P and swims at a constant speed of 0.72m/s relative to the water and at right angles to the current.
When the swimmer is crossing the river, his actions produce a constant forward force on his body.
Explain why he moves at a constant speed. [Total: 9]
friction (of water backwards) OR resistance (on swimmer backwards) (friction / resistance) balances forward force OR (there is) no resultant force