Space Time & Motion A.3 Work Energy and Power (id: 956fb62ae)

本题目来源于试卷: Space Time & Motion A.3 Work Energy and Power，类别为 IB物理学

[单选题]
A 74 kg boy starts to ride a 6.0 kg bicycle from rest. The graph shows how the acceleration $a$ of the bicycle varies with the distance travelled $x$.


What is the total work done by the boy?

A. $0.3\,k\,J$
B. $3.7\,k\,J$
C. $4.0\,k\,J$
D. $6.0\,k\,J$


参考答案:  C


本题详细解析:
Expianation:

Work Done = (Force $\times$ Distance) = (Mass $\times$ Acceleration $\times$ Distance)

(Acceleration $\times$ Distance) is the area under the graph.

Work done is (Mass $\times$ Graph Area) = (74+6)(50) = 4000 J = 4 kJ

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