Answer:
The speed of the combined honey drop after the collision is 9.05 m/s.
Step-by-step explanation:
Given that,
The masses and velocities of the drops are
![m_(1)=31.5\ g](https://img.qammunity.org/2020/formulas/physics/high-school/p39gwswhyimtzwndeovbfofxbja60vszf3.png)
![v_(1)=12.7\ m/s](https://img.qammunity.org/2020/formulas/physics/high-school/hb5m1sxhf7vf8zcj0cl5jsfedrkfqm8lj7.png)
![m_(2)=49.9\ g](https://img.qammunity.org/2020/formulas/physics/high-school/df7x4k1wszkcx6rybma0ctsezn1hrrf35r.png)
![v_(1)=12.5\ m/s](https://img.qammunity.org/2020/formulas/physics/high-school/ci3qpk8mhvnryor7zv7o6xeuhnufoktkqk.png)
![m_(1)=78.1\ g](https://img.qammunity.org/2020/formulas/physics/high-school/27wvydfu50up288kuz2d3aq3d4exr9td2b.png)
![v_(1)=15.9\ m/s](https://img.qammunity.org/2020/formulas/physics/high-school/xm98ma3c2q8nvks15rn66gh34v6odkiq0l.png)
We need to calculate the total mass
Using formula of masses
![m=m_(1)+m_(2)+m_(3)](https://img.qammunity.org/2020/formulas/physics/high-school/o246eal36u4d68299lvcc8xq39e5o09sar.png)
Put the value into the formula
![m=31.5+49.9+78.1](https://img.qammunity.org/2020/formulas/physics/high-school/k5685lll0wm9h19qt8b8hgjn6bdwb6f8ns.png)
![m=159.5\ g](https://img.qammunity.org/2020/formulas/physics/high-school/htrsa72box4ehlm7vfvjd89r2vwsv7liqj.png)
We need to calculate the velocity in x- direction
Using conservation of momentum
![m_(1)v_(1)=(m_(1)+m_(2)+m_(3))v_(x)](https://img.qammunity.org/2020/formulas/physics/high-school/3or0e8aelq99qepwr2djgftkiuudhkclcv.png)
![v_(x)=(m_(1)v_(1))/(m_(1)+m_(2)+m_(3))](https://img.qammunity.org/2020/formulas/physics/high-school/h2id7woi4ldojdam7sulgmklvi6xxs4ks4.png)
Put the value into the formula
![v_(x)=(31.5*12.7)/(159.5)](https://img.qammunity.org/2020/formulas/physics/high-school/s2nw583lirbb5jcmstavlbx97i7pljxk3q.png)
![v_(x)=2.50\ m/s](https://img.qammunity.org/2020/formulas/physics/high-school/o3mgk4t74xgka1w3fb3ec6y12lh62x0au0.png)
We need to calculate the velocity in y- direction
Using conservation of momentum
![m_(2)v_(2)=(m_(1)+m_(2)+m_(3))v_(y)](https://img.qammunity.org/2020/formulas/physics/high-school/yxdxva2115ch1lh8icusmyhf1b56nuelxd.png)
![v_(y)=(m_(2)v_(2))/(m_(1)+m_(2)+m_(3))](https://img.qammunity.org/2020/formulas/physics/high-school/nwwaj7z7pzc1rzgpln2oovvj5pry8caozp.png)
Put the value into the formula
![v_(y)=(49.9*12.5)/(159.5)](https://img.qammunity.org/2020/formulas/physics/high-school/w82o40jx9709h338vexbcxsfeetzwpc2qw.png)
![v_(y)=3.91\ m/s](https://img.qammunity.org/2020/formulas/physics/high-school/6hmis7ddku677vl5nu65volee8ji4jw1pa.png)
We need to calculate the velocity in z- direction
Using conservation of momentum
![m_(3)v_(3)=(m_(1)+m_(2)+m_(3))v_(z)](https://img.qammunity.org/2020/formulas/physics/high-school/bmc3q6vtzt91cnh8ldw0odpw24xsr2ihhv.png)
![v_(z)=(m_(3)v_(3))/(m_(1)+m_(2)+m_(3))](https://img.qammunity.org/2020/formulas/physics/high-school/zbhg4fntyx5p4wgiee9798an2cedn5v6f6.png)
Put the value into the formula
![v_(z)=(78.1*15.9)/(159.5)](https://img.qammunity.org/2020/formulas/physics/high-school/3gq5r6cwmrc41wos5x2c6fwoo6b2uu7abq.png)
![v_(z)=7.78\ m/s](https://img.qammunity.org/2020/formulas/physics/high-school/wjvuy6c6ap5k2lh5uwipga8cuo8zps77hi.png)
We need to calculate the combined honey drop after the collision
Using formula of velocity
![v=v_(x)+v_(y)+v_(z)](https://img.qammunity.org/2020/formulas/physics/high-school/pyluk11b41ldoj2i0u1jern9a7caw1u6wo.png)
Put the value into the formula
![v=2.50i+3.91j+7.78k](https://img.qammunity.org/2020/formulas/physics/high-school/i5abu9see9cbm5bd0rd4dmzlcs1q4o50d3.png)
The magnitude of velocity
![v=√((2.50)^2+(3.9)^2+(7.78)^2)](https://img.qammunity.org/2020/formulas/physics/high-school/ax6flfeoew9unsac3sqgnzssd0xk238q5f.png)
![v=9.05\ m/s](https://img.qammunity.org/2020/formulas/physics/high-school/kldecm337z6pjh66n16nq9zrphege35br7.png)
Hence, The speed of the combined honey drop after the collision is 9.05 m/s.