When the elevator in the mine starts to rise at a constant speed from a standstill, and reaches 4m / s after 5S, it rises at this speed for 20s, then rises at a constant speed, and stops at the wellhead after 4S, then the depth of the mine is______ m．

When the elevator in the mine starts to rise at a constant speed from a standstill, and reaches 4m / s after 5S, it rises at this speed for 20s, then rises at a constant speed, and stops at the wellhead after 4S, then the depth of the mine is______ m．

The displacement in the process of uniform acceleration rising is X1 =. VT = 0 + 42 × 5m = 10m & nbsp; & nbsp; & nbsp; the displacement in the process of uniform acceleration rising is x2 = VT = 4 × 20m = 80m & nbsp; & nbsp; & nbsp; the displacement in the process of uniform deceleration rising is X3 =. VT = 4 + 02 × 4m = 8m, then the mine depth is h = X1 + x2 + X3 =