Acceleration
Q1.
(a)     The diagram shows an aircraft and the horizontal forces acting on it as it moves along a runway. The resultant force on the aircraft is zero.
 
(i)      What is meant by the term resultant force?
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(1)
(ii)     Describe the movement of the aircraft when the resultant force is zero.
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(1)
(b)     The aircraft has a take-off mass of 320 000 kg. Each of the 4 engines can produce a maximum force of 240 kN.
Calculate the maximum acceleration of the aircraft.
Show clearly how you work out your answer and give the unit.
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Acceleration = ________________________
(3)
(c)     As the aircraft moves along the runway to take off, its acceleration decreases even though the force from the engines is constant.
Explain why.
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(2)
(Total 7 marks)