2. A javelin is thrown through an angle of 30o to the horizontal. Find the time taken by the javelin to reach the maximum height if the initial velocity is 60ms-1 [ take g =10 ms-1]

Respuesta :

Answer:

3 seconds

Explanation:

The initial velocity is 60 m/s at an angle of 30° to the horizontal, so we can calculate the initial velocity in the vertical direction as

Viy = Vi sin(θ)

Viy = 60 sin(30)

Viy = 60(0.5)

Viy = 30 m/s

Then, we can use the following equation to calculate the time that it takes to reach the maximum height.

[tex]\begin{gathered} v_{fy}=v_{iy}-gt \\ v_{fy}+gt=v_{iy} \\ gt=v_{iy}-v_{fy} \\ \\ t=\frac{v_{iy}-v_{fy}}{g} \end{gathered}[/tex]

At a maximum height the vertical velocity is 0 m/s, so replacing viy = 30 m/s, vfy = 0 m/s and g = 10 m/s², we get

[tex]\begin{gathered} t=\frac{30\text{ m/s-0m/s}}{10\text{ m/s}^2} \\ \\ t=\frac{30\text{ m/s}}{10\text{ m/s}^2} \\ \\ t=3\text{ s} \end{gathered}[/tex]

Therefore, the answer is 3 seconds