A 5500 kg helicopter accelerates upward at 0.50 #m##/##s^2# while lifting a 1200 kg car. What is the lift force exerted by the air on the rotors? What is the tension in the cable that connects the car to the helicopter, ignoring mass?

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Answer 1 · 2017-12-16T14:21:34

The lift force is #=69.01kN#. The tension in the cable is #=12.36kN#

The mass of the helicopter is #m_1=5500kg#

The mass of the car is #m_2=1200kg#

The upward acceleration of the helicopter is #a=0.5ms^-2#

The acceleration due to gravity is #g=9.8ms^-2#

Let the lift force be #=FN#

Resolving in the upwards direction #uarr^+#

#F-(m_1+m_2)g=(m_1+m_2)a#

#F=6700(9.8+0.5)=69010N#

Let the tension in the cable be #=TN#

Resolving in the upwards direction #uarr^+#

#T-m_2g=m_2a#

#T=m_2(g+a)=1200*(9.8+0.5)=12360N#