An elevator of mass M is accelerated upwards by applying a force F.A m – InterviewSolution

InterviewSolution

1.	An elevator of mass M is accelerated upwards by applying a force F.A mass m initially situated at a height of 1 m above the floor the elevator is falling freely. It will hit the floor of the elevator after a time equal toA. `sqrt((2M)/(F+mg))`B. `sqrt((2M)/(F-mg))`C. `sqrt((2M)/(F))`D. `sqrt((2M)/(F+Mg))`
Answer» Correct Answer - C `a_(e)=(F)/(m)uarr` `a_(s)=-gdarr` `a_(s//e)=a_(s)-a_(e)=(F)/(m)+g=(F+Mg)/(M)` `s=ut+(I)/(2)at^(2)` `1=(1)/(2)((F+Mg)/(M))t^(2)` `t=sqrt(2(M)/(F+Mg))`

Discussion

No Comment Found

Related InterviewSolutions

In Fraumhroffer diffraction pattern due to a single slit, the screen is at distance of 100 cm from the slit and slit is illuminated by `lambda=5893Å`. The width of the slit is 0.1 mm. Then separation between central maxima and the first secondary minimaA. `0.5893 cm`B. `5.893 cm`C. `0.2946 cm`D. `2.946 cm `
Four functions given below descirbe motion of a particle. (I)`y=sinomega-cosomegat,(II)y=sin^(3)omegat,` (III) `y=5cos((3pi)/(4)-3omegat),(IV)y=1+omega+omega^(2)t^(2)` Therefore, simple harmonic motion is represented byA. only (I)B. (I),(II) and (III)C. (I) and (III)D. (I) and (II)
The resistivity of iron is `1 xx 10^(-7) ohm-m` . The resistance of a iron wire of particular length and thickness is 1 ohm . If the length and the diameter of wire both are doubled, then the resistivity in ohm-m will beA. `1xx10^(-7)`B. `2xx10^(-7)`C. `4xx10^(-7)`D. None of these
An elevator of mass M is accelerated upwards by applying a force F.A mass m initially situated at a height of 1 m above the floor the elevator is falling freely. It will hit the floor of the elevator after a time equal toA. `sqrt((2M)/(F+mg))`B. `sqrt((2M)/(F-mg))`C. `sqrt((2M)/(F))`D. `sqrt((2M)/(F+Mg))`