APPLICATION OF NEWTONS SECOND LAW OF MOTION

An elevator and its load has a total mass of 800kg.the elevator is originally moving downward at 10m/s and it is broyght to rest at constant acceleration in distance of 25.0m

Find the tension T in the supporing cable

My teacher said that the answers should be this,all we need to do is the solution.
A=+2.00m/s2 (squared)
T=9.440 N

Thank you.


Sagot :

For acceleration, we have: A = (V^2 - Vo^2)/2(X) --> A = [(0)^2 - (-10)^2]/2(25) = -100/50 = -2.00 m/s^2. Just ignore the negative sign, it just means that the elevator is moving downward. For the tension, we have 3 forces acting on the elevator, the Tension and the Force pointing upward and the Weight pointing downward. So we write: T + - F + (-W) = 0 --> W - F = T --> (800 kg)(9.81 m/s^2) + (800 kg)(2 m/s^2) = T --> 9448 N = T.