b. You know the mass, velocity, starting height of the clay/ball combo. compute time to hit earth
you can use a number of equations, but if you think, on the way down at 10m, it will have the same velocity but down...
vf^2=vi^2+2ad
Vf^2=30.09^2+9.8*2*10
c. I don't understand the q.
You throw a 0.15 kg ball straight upward from ground level with an initial speed of 15 m/s. (Yes, from ground level. This is to make the calculations easier. If it bothers you, imagine you are standing in a dugout.) Your friend throws a 0.09 kg lump of clay upward after it. The ball is at a height of 10 m, coming back down, when the clay, going 25 m/s upward at that instant, strikes the ball and sticks to it. Assume the interaction is instantaneous, and neglect air resistance. (The easiest way to do this problem is from energy and momentum laws, not kinematics!)
(a)What is the velocity of the ball/clay combination immediately after the collision?
For this one, I used m1vi1+m2vi2=(m1+m2)vf
vf=30.09 m/s
(b)What is the speed of the combination right before it strikes the earth?
I don't know what equation I could use without using kinematics?
(c)How fast, and in which direction, would a bird have to be flying for the momentum of the system
to appear to her to be zero right before the collision?
1 answer