Answer:
35 kg
Explanation:
The momentum of an object is given by:
[tex]p=mv[/tex]
where
p is the momentum
m is the mass of the object
v is its velocity
In this problem:
p = 140 kg m/s is the momentum of the dart
v = 4 m/s is its velocity
Solving for v, we find its mass:
[tex]m=\frac{p}{v}=\frac{140}{4}=35 kg[/tex]
