Minimum mass of a block

[Ishfa]

Homework Statement

Classical Mechanics

Relevant Equations

s= v0t + 1/2 gt^2

 

[BvU]

Hi,

See rules etc: explain (in words) what you are doing; make a sketch (Height versus time) of what happens.

We are a bit reluctant to reverse engineer your writings, so you have to help us help you


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[kuruman]

The collision time happens once and cannot be double-valued.
You can make your life simpler and avoid quadratics if you consider the velocities.

1. Write expressions for the velocity of each can as a function of time.
2. How is the velocity of the first can v₁ related to the velocity of the second can v₂ at the time of the collision?

 

[haruspex]

In your fifth equation, the one ending …16-1)=0, check where that -1 comes from. It should be something else.
Also, having obtained a quadratic in t that involves the unknown $v_0$, bear in mind that what you want to find is t, not $v_0$. So which should you be trying to eliminate?

Btw, what has this to do with "minimum mass of a block"?

 

[kuruman]

Btw, what has this to do with "minimum mass of a block"?

The minimum mass may have something with another part of the problem, e.g (b) Find the minimum value of the second mass so that the time of flight after the collision is $t_2$ seconds if the masses stick together (or some such thing.)