[单选题]
A spring of negligible mass and length of $l_0$ is attached to a fixed point. When the spring is extended by an external force F, the length of the spring increases to $l$. The graph shows how the length of the spring varies with the tension in spring. The tension in the spring is equal to $k△l$, where k is a constant and $△l$ is the extension of the spring.
What are the gradient and y-intercept of the graph?
A.
B.
C.
D.
参考答案: B
本题详细解析:
The y-intercept is the length of the spring when there is no external force. Therefore, the y-intercept is lo
Gradient is ΔxΔy on the graph
Hooke's Law states that F=kΔx and in this case Δx=l−lo