A canoeist on a lake throws a 0.145 kg baseball at 20.0 m/s to a friend in a different canoe. Each canoe with its contents has a mass of 120 kg, and is at rest initially. How fast is the first canoe moving after the pitch, assuming no friction with the water?
this can be solve using momentum, where momentum = mv
where m is the mass of the object
and v is the velocity of the object
m1v1 + m2v2 = mfvf
( 0.145 kg )( 20 m/s ) + ( 120 kg )( 0 m/s) = ( 120 + 0.145 kg)vf
solve for vf
2.9 = 120.145vf
vf = 0.024 m/s
Answer
Explanation :
It is given that:
mass of baseball, \(m_1=0.145\ Kg\)
mass of canoe, \(m_2=120\ Kg\)
velocity of baseball, \(u_1=20\ m/s\ Kg\)
velocity of canoe, \(u_1=0\)
Let v is the velocity of the first canoe moving after the pitch.
Now, using conservation of momentum as
\(m_1u_1+m_2u_2=(m_1+m_2)v\)
\(( 0.145 kg )( 20 m/s ) + ( 120 kg )(0) = ( 120 + 0.145 kg)v\)
\(2.9\ kgm/s^2+0=120.45\ kg\ v\)
\(v=0.024\ m/s\)
Hence, it is the required solution.