The answer they are looking for is the last one. However the last two are technically correct but the third one would result in negative work.
Answer:
The effect of your walking will create a force on the airline acting downwards, due to the weight. By Newton's thirds law the airline will exert an equal and opposite reaction force directed downwards.
Explanation:
The weight of all the passengers acts downwards on the floor of the Airplane.
The Airplane exerts an equal and opposite force on the passengers, with the help of its propulsion due to which the flight keeps on flying without falling down.
Hence by changing the frame of reference we can observe the force which is responsible for the reaction.
Answer:
F = 19.1 N
Explanation:
To find the force exerted by the string on the block you use the following formula:
(1)
k: spring constant = 95.5 N/m
x: displacement of the block from its equilibrium position = 0.200 m
you replace the values of k and x in the equation (1):

Hence, the force exterted on the block is 19.1 N
One of your 5 senses because your 5senses are hearing, smelling, seeing, taste, touching
1000 litres of water can fill a tank of 1m3 capacity because water has a density of 1000kg/m3 and as 1 kg water = 1 liter ,
1000 liter of water can fill a tank of 1m3