Question

This is a graph of a marble traveling across a smooth surface. What is the average speed of this marble?

Answer 1

Since it is a smooth marble and basing from the graph, it has a constant slope, you could just get any two points along the line and get its slope since speed is Δd/Δt. Let the points be (4,6) and (6,9). Thus,

Δd/Δt = (9-6)/(6-4) = 1.5

Thus, the average speed is 1.5 m/s.

Answer 2

Answer:

v = 1.5 m/s

Explanation:

The attached figure shows a distance time graph. The motion of marble is uniform. It covers equal distance in equal interval of time. The average speed of the car is calculated by finding its slope in d-t graph.

From the attached figure,

$d_1=6\ m$

$d_2=3\ m$

$t_1=4\ s$

$t_2=2\ m$

Slope of the graph is given by :

$slope=\dfrac{d}{t}=\dfrac{d_1-d_2}{t_1-t_2}$

$slope=v=\dfrac{6-3}{4-2}$

v = 1.5 m/s

So, the average speed of this marble is 1.5 m/s.