Blythe and Geoff are ice-skating together. Blythe has a mass of 40 kg and Geoff has a mass of 79 kg. Blythe pushes Geoff in the chest when both are at rest, causing him to move away at a speed of 5 m/s.
Answer:
Speed of Blythe is 9.8 m/s.
Explanation:
Mass of Blythe =40 kg
Mass of Geoff = 79 kg
Speed = 5 m/s
Suppose, we determine the Blythe's speed after she pushes Geoff
Since, initial momentum is zero final momentum should be zero.
Using momentum of conservation
\(m_{B}v_{B}+m_{G}v_{G}=0\)
\(v_{B}=-\dfrac{m_{G}v_{G}}{m_{B}}\)
Put the value into the formula
\(v_{B}=-\dfrac{79\times5}{40}\)
\(v_{B}=-9.8\ m/s\)
Negative sign shows that he move in direction opposite to Geoff.
Hence, Speed of Blythe is 9.8 m/s.