Solve a Physics Problem: Finding Time in the Air for a Kangaroo Jumping 3.0m

[rakesh44]

Homework Statement

A kangaroo jumps to a vertical height of 3.0 m. How long was it in the air before returning to Earth?

Homework Equations

The Attempt at a Solution

i got 5.622 as an answer but that's not right.

 

[Fazza3_uae]

This Question Is been Repeated but with different values .

Please Check THis link it may help you .

https://www.physicsforums.com/showthread.php?t=254219

 

[tomcue]

I would approach this problem by using the equation for displacement in the vertical direction, which is given by d = v0t + (1/2)at^2, where d is the displacement, v0 is the initial velocity, a is the acceleration (in this case, due to gravity), and t is the time. We can rearrange this equation to solve for t, which gives us t = (v0 ± √(v0^2 + 2ad)) / a. Since we know that the kangaroo starts and ends at rest (v0 = 0), we can simplify this to t = √(2d/a). Plugging in the given values of d = 3.0 m and a = -9.8 m/s^2 (since the acceleration due to gravity is directed downwards), we get t = √(2(3.0 m)/(-9.8 m/s^2)) = 0.78 seconds. Therefore, the kangaroo was in the air for 0.78 seconds before returning to Earth. It is important to note that the negative sign in the acceleration indicates that the acceleration is in the opposite direction of the displacement, which is why we use -9.8 m/s^2 in the calculation.