Answer:
0.7 m/s
Explanation:
We can solve the problem by using conservation of momentum.
Before the collision, the momentum of the first tackler is:
![p_1 = m_1 v_1 =(110 kg)(2.5 m/s)=275 kg m/s](https://tex.z-dn.net/?f=p_1%20%3D%20m_1%20%20%20v_1%20%3D%28110%20kg%29%282.5%20m%2Fs%29%3D275%20kg%20m%2Fs)
while the momentum of the second tackler is
![p_2 = m_2 v_2 =(82 kg)(-5.0 m/s)=-410 kg m/s](https://tex.z-dn.net/?f=p_2%20%3D%20m_2%20v_2%20%3D%2882%20kg%29%28-5.0%20m%2Fs%29%3D-410%20kg%20m%2Fs)
Note that we used a negative sign because the direction of the second tackler is opposite to that of the first tackler.
Therefore, the total momentum before the collision is
![p_i = p_1 +p_2 =275 kg m/s -410 kg m/s=-135 kg m/s](https://tex.z-dn.net/?f=p_i%20%3D%20p_1%20%2Bp_2%20%3D275%20kg%20m%2Fs%20-410%20kg%20m%2Fs%3D-135%20kg%20m%2Fs)
Since the total momentum is conserved, this is also equal to the final total momentum :
![p_f = -135 kg m/s](https://tex.z-dn.net/?f=p_f%20%3D%20-135%20kg%20m%2Fs)
Which is also equal to
![p_f = (m_1 +m_2 )v_f](https://tex.z-dn.net/?f=p_f%20%3D%20%28m_1%20%2Bm_2%20%29v_f)
since the two tacklers continue their motion together with final velocity vf. Re-arranging the previous equation, we can find the the new velocity of the two tacklers:
![v_f = \frac{p_f}{m_1 +m_2}=\frac{-135 kg m/s}{110 kg + 82 kg}=-0.7 m/s](https://tex.z-dn.net/?f=v_f%20%3D%20%5Cfrac%7Bp_f%7D%7Bm_1%20%2Bm_2%7D%3D%5Cfrac%7B-135%20kg%20m%2Fs%7D%7B110%20kg%20%2B%2082%20kg%7D%3D-0.7%20m%2Fs)
and the negative sign means the direction is the one of the second tackler.
The answer is b !!!! Hope it helps
C. is correct. when you make a pizza, you see the the meat or pepperoni or cheese heating up and sometimes melted. (thats physical). on the inside the crust in heated and the toppings are cooked (chemical)