Solving Jumping Bean Physics Problems

[shoook]

A jumping bean jumps vertically upward from the edge of a table. It has a speed of 10 m/s when it reaches half of its maximum height.
a. How high does it rise?
b. What is its velocity and acceleration 1 second after it jumps?
c. 3 seconds after?
d. What is its average velocity during the first half second?

Okay so I'm a big noob. I think the acceleration is 9.8 m/sec^2 due to gravity. I think I can add 9.8 m for every second it rises but I'm not sure. Any help at all with this problem is greatly appreciated.

 

[Astronuc]

I think I can add 9.8 m for every second it rises but I'm not sure.

Not quite. The bean jumps vertically, but gravity is acting downward, so once the bean is launched with some initial velocity, it starts slowing down.

Let H = maximum height, at which point the vertical velocity is zero.

at h = H/2, v = 10 m/s, and the acceleration, g = 9.8 m/s².

How about writing some equations that relate height h(t), time t and vertical velocity v(t)?

 

[Saketh]

Do you know the kinematic equations?

As in \Delta x = v_0 t + \frac{at^2}{2}?

If you don't, then I can see why you're having trouble with this problem.

 

[shoook]

No I don't. I've only been taught 5 very basic physics formulas such as
a= Vf - Vi/t