A cat leaps into the air to catch a bird with an initial speed of 2.74 m/s at an angle of 60.0° above the ground. What is the highest point of the cat’s trajectory?


A. 0.19 m


B. 10.96 m


C. 0.58 m


D. 0.29 m


Respuesta :

Answer: D. 0.29 m

Explanation:

We will use the following equations to describe the leap of the cat:

[tex]y=V_{o}sin\theta t-\frac{gt^{2}}{2}[/tex]   (1)

[tex]V_{y}=V_{oy}-gt[/tex]   (2)

Where:

[tex]y[/tex]  is the height of the cat  

[tex]V_{oy}=V_{o}sin\theta[/tex] is the cat's initial velocity

[tex]\theta=60\°[/tex]

[tex]g=9.8m/s^{2}[/tex]  is the acceleration due gravity

[tex]t[/tex] is the time

[tex]V_{y}[/tex] is the y-component of the velocity

Now the cat will have its maximum height [tex]y_{max}[/tex] when [tex]V_{y}=0[/tex]. So equation (2) is rewritten as:

[tex]0=V_{oy}-gt[/tex]   (3)

Finding [tex]t[/tex]:

[tex]t=\frac{V_{oy}}{g}=\frac{V_{o}sin\theta}{g}[/tex]   (4)

[tex]t=\frac{2.74 m/s sin(60\°)}{9.8m/s^{2}}[/tex]   (5)

[tex]t=0.24 s[/tex]   (6)

Substituting (6) in (1):

[tex]y_{max}=(2.74 m/s)sin(60\°) (0.24 s)-\frac{(9.8m/s^{2})(0.24 s)^{2}}{2}[/tex]   (7)

Finally:

[tex]y_{max}=0.287 m \approx 0.29 m[/tex]   (8)