Question

2 derek launches a puck across a sheet of ice. the puck has an initial velocity of 12 m/s in the positive direction the puck has a constant rate of acceleration of -0.40 m/s² after 6.5 seconds, what is the pucks displacement?
78 meters
61 meters
-8.5 meters
70 meters

Explanation:

Step1: Recall the displacement formula

The formula for displacement \(s = v_0t+\frac{1}{2}at^{2}\), where \(v_0\) is the initial velocity, \(t\) is the time, and \(a\) is the acceleration.
Given \(v_0 = 12\space m/s\), \(a=- 0.40\space m/s^{2}\), and \(t = 6.5\space s\).

Step2: Substitute the values into the formula

First, calculate \(v_0t\): \(v_0t=12\times6.5 = 78\space m\)
Second, calculate \(\frac{1}{2}at^{2}\): \(\frac{1}{2}\times(-0.40)\times(6.5)^{2}=- 0.2\times42.25=-8.45\space m\)

Step3: Calculate the displacement \(s\)

\(s=v_0t+\frac{1}{2}at^{2}=78+( - 8.45)=69.55\approx70\space m\)

Answer:

70 meters