Answer:
2.45 m/s
Explanation:
From the law of conservation of momentum,
The total momentum before the grab = Total momentum after the grab.
mu+m'u' = V(m+m')................... Equation 1
Where m = mass of Erica, m' = mass of Danny, u = initial velocity of Erica, u' = initial velocity of Danny, V = common velocity after garb
Make V the subject of the equation
V = (mu+m'u')/(m+m')............. Equation 2
Given: m = 37 kg, m' = 49 kg, u = 0 m/s(at the maximum height), u' = 4.3 m/s
Substitute into equation 2
V = (37×0+49×4.3)/(37+49)
V = 210.7/86
V = 2.45 m/s
Hence their speed just after the grab = 2.45 m/s
