Question

question 12 (1 point)
a roller coasters accelerates from an initial velocity of 6.0 m/s to a final velocity of 70 m/s over 4 seconds. whats the acceleration?
a) 24 m/s² b) 18 m/s²
c) 16 m/s² d) 16 m/s
question 13 (1 point)
for the position - time graph of an object moving in one dimension, which of the following properties would imply that the object has motion with nonuniform velocity?
(a) the graph is a straight line with a slope of 3.
(b) the graph is a curve.
(c) the graph is a horizontal line.
(d) the graph is a negative line.

Explanation:

Question 12

Step1: Recall the acceleration formula

The formula for acceleration \(a=\frac{v - u}{t}\), where \(v\) is the final velocity, \(u\) is the initial velocity, and \(t\) is the time.

Step2: Substitute the given values

Given \(u = 6.0\space m/s\), \(v=70\space m/s\), and \(t = 4\space s\). Then \(a=\frac{70 - 6}{4}=\frac{64}{4}\)

Step3: Calculate the value

\(\frac{64}{4}=16\space m/s^{2}\)

In a position - time graph, the slope of the graph represents velocity. A straight - line graph (whether with a positive constant slope, negative constant slope, or zero slope (horizontal line)) implies a constant velocity. A curve in the position - time graph means that the slope (velocity) is changing at different points of time.

Answer:

C. \(16\space m/s^{2}\)

Question 13