Question

Kangaroo can jump 2.5 m vertically. What must be the initial velocity of the kangaroo? how is coming 9.8 m/s2​

Answer 1

Explanation:

h=2.5m

v^2-u^2=2as

v=0

so u=√2gh

u=√49= 7m/s

Answer 2

Answer:

The initial velocity of the kangaroo must be 7 m/s.

Explanation:

a = 9.8 m/s²

s = 2.5 m

v = 0 m/s

v² = u² + 2as

=> (0)² = u² + 2 * (-9.8) * 2.5

=> 0 = u² - 5 * 9.8

=> 0 = u² - 49

=> u² = 0 + 49

=> u² = 49

=> u = 7 m/s

So,

The initial velocity of the kangaroo must be 7 m/s.

Here, negative sign of acceleration shows that it is in the opposite direction of the velocity.

When acceleration is in opposite direction of the velocity, its value is taken as 9.8 m/s².