Answer:
Step-by-step explanation:
Here is the information we have.
Skateboard: 1.4 kg, velocity = 19 m /s
You: weight: 52 kg, veclocity = 19m/s (since you are riding the skateboard)
Now the momentum of an object is given by
where
m = mass
v = velocity
Now in our case, the momentum of the skateboard is
![p_{\text{skateboard}}=1.4\operatorname{kg}\cdot19m/s=26.6\operatorname{kg}\cdot m/s]()
Your momentum is
![p_{\text{you}}=52\operatorname{kg}\cdot19m/s=988\operatorname{kg}\cdot m/s\text{.}]()
Therefore, the total momentum of you and the skateboard is
![\Rightarrow\boxed{p_{\text{total}}=1014.6\operatorname{kg}\cdot m/s\text{.}}]()
The combined mass of the skateboard and you is
![m_{\text{total}}=m_{\text{you}}+m_{\text{skateboard}}=52\operatorname{kg}+1.4\operatorname{kg}]()
![\Rightarrow\boxed{m_{\text{total}}=53.4\operatorname{kg}\text{.}}]()
Hence, to summerise
total momentum = 1014.6 kg * m/s
combined mass = 53.4 kg.