- #1

jisbon

- 476

- 30

- Homework Statement
- Ball of 8kg explodes in 2 pieces at height of 30m. Both pieces fly out vertically, after 2 seconds, one piece reach the ground while the other is 16m above ground. Find mass of small piece that hits the ground first.

- Relevant Equations
- Change in KE = Final KE

Initial momentum = final momentum

So to start off,

the piece that hits the ground first is the smaller piece.

So I can form the equations where:

where

##8(u_{8kg})= m_{1}v_{1}+m_{2}v_{2}##

##m_{1}+m_{2}= 8##

After 2 seconds,

##30 = v_{1}(2)+\frac{1}{2}at^{2}##

##v_{1}= 5.2m/s##

##(30-16) = v_{2}(2)+\frac{1}{2}at^{2}##

##v_{2}= 2.8m/s##

Am I supposed to craft any more equations from here?

The KE equations:

Change in KE = final KE

Change in KE

##(\frac{1}{2}m_{1}5.2^2) +(\frac{1}{2}m_{2}2.8^2) - (\frac{1}{2}mu^2)##

the piece that hits the ground first is the smaller piece.

So I can form the equations where:

where

##8(u_{8kg})= m_{1}v_{1}+m_{2}v_{2}##

##m_{1}+m_{2}= 8##

After 2 seconds,

##30 = v_{1}(2)+\frac{1}{2}at^{2}##

##v_{1}= 5.2m/s##

##(30-16) = v_{2}(2)+\frac{1}{2}at^{2}##

##v_{2}= 2.8m/s##

Am I supposed to craft any more equations from here?

The KE equations:

Change in KE = final KE

Change in KE

##(\frac{1}{2}m_{1}5.2^2) +(\frac{1}{2}m_{2}2.8^2) - (\frac{1}{2}mu^2)##