Physics MC Question

2007-04-06 7:35 am

A bead is dropping in medium 1 with a uniform speed of 1 m s-1 for 2.5 s. Then it enters into air and falls freely under gravity for 2 m . Finally, it enters medium 2 and immediately moves with uniform speed for 1.5 s. Find the total distance the bead has traveled.

更新1:

hoping that the answerers can show the steps of calculation ......

回答 (1)

h9613374

2007-04-06 7:44 am

✔ 最佳答案

14.1 m

2007-04-05 23:56:43 補充：
s=ut (1/2)(at^2)In medium 1, u=1 (given), t=2.5 (given), a=0(due to uniform speed)Distance travel in medium 1 = (1)(2.5) 0 = 2.5 m

2007-04-05 23:57:17 補充：
Distance travel in air = 2 m (given)v^2 = u^2 2asIn air, u=1(same as in medium 1 due to uniform speed before enter air), a=10(take g=10), s=2(given)v = speed immediately before entering medium 2 = square root of (1"^2 2x10x2) = square root of 41 = 6.4031

2007-04-05 23:57:38 補充：
s=ut (1/2)(at^2)In medium 2, u=6.4031, t=1.5 (given), a=0(due to uniform speed)Distance travel in medium 2 = (6.4031)(1.5) = 9.60465Total distance = 2.5 m 2 m 9.60465 m = 14.1 m (correct to 1 decimal place)

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