As you are driving to school one day, you pass a construction site for a new building and stop to watch for a few minutesA crane is lifting a batch of bricks on a pallet to an upper floor of the buildingSuddenly, a brick falls of the rising palletYou clock the time it takes for the brick to hit the ground at 2.5 secondsThe crane, fortunately, had height markings and you see the brick fell off the pallet at a height of 22 meters above the groundA falling brick can be dangerous, and you wonder how fast the brick was going when it hit the groundYou quickly calculate the answer.So my problem with this is if there is enough info to solve because apparently, the brick appears to rise, so it will have a nonzero velocity at 22m above the ground.
Aircraft are built to take positive G more than negative since that is the upright positionAerobatic aircraft are built to take +/- 10 gA regular Cessna for example is built to hang with positive G and not structurally for negativeA negative g puts the weight on the opposite side of the wing.
You're rightNegative G puts force on the wing in the opposite direction, which most aircraft are usually not designed for Of course zero-G would have the least aircraft damage unless some systems are gravity fed.
You have to calculate the answer quicklySum of the speeds 2 Average speed 2 22/ 2.5 17.6 m/s Difference (or increase) in speed 9.82.5 24.5m/s Final speed (17.6 + 24.5.) / 2 21.05m/s - To know the initial speed (17.6 - 24.5.) /2 -3.45m/s (minus indicates upward direction )
To imaging negative G, imagine the plane pulling positive G but flying invertedIt is not that it is negative as such, it is that it is a high negativeThat said, there are systems that are not meant to stand a lot of negative G'sFor instance, engine lubrication system and fuel pumpThose are designed to expect the fluid to be found somewhere in a tankFly with a lot of negative G, or do so for a sustained period of time, and you could starve the engine or other systems from coolant and lubricationAlso, pilots are also designed for positive GGet a lot of positive G, and a flight suit can be used to apply pressure on the legs to prevent blood from pooling there and delay pilot's black outPull negative G and the blood would pool in the headNot only can this cause a red-out, but the pilot can get a very nasty headacheThat, by the way, is the reason an airplane diving to attach towards the ground would flip almost to reverse, so that the dive applies positive G instead of negative.
Acceleration in any direction can cause structural damage if it is great enoughThe aircraft doesn't care much whether it is positive or negative; it's the total stress and the place where it is applied that countsNo, negative Gs do not put less weight on the airplaneThey simply accelerate it downward at more than the acceleration due to gravityIn level flight, the aircraft is subjected to 1 positive GIf it starts to accelerate downwards, the positive G diminishes to zero and then goes negativeAn acceleration of zero positive G or between zero and 1 positive G normally isn't a problem (except possibly for things like fuel that depend on gravity)Negative Gs are a potential problemNegative Gs are also more hazardous for human beings.
