Answer:
1) v = 0.49 m/s
2) v = 2.5 Km/h
Explanation:
1) Given,
Let the initial velocity of the dog and canoe be zero, hence the total momentum is also equal to zero.
The final velocity of the dog, v = 1.4 m/s
The mass of the dog, m = 16 Kg
The mass of the canoe, M = 45 Kg
The final velocity of the canoe, V = ?
According to the law of conservation of linear momentum,
MV + mv = 0
Substituting the given values in the above equation
45 x V + 16 x 1.4 = 0
V = -22.4 / 45
V = -0.49 m/s
The negative sign indicates that the canoe moves in the direction opposite to that of dog
Hence the velocity of the canoe, V = 0.49 m/s
2) Given,
Let the mass of the person be 'm'
The mass of his buddy is also 'm'
The initial velocity of the person, u = 5 Km/h
The initial velocity of his buddy, U = 0
According to the laws of conservation of linear momentum,
Since the person holds onto the buddy, their final velocity is combined. Let it be 'v'
mu + mU = mv + mv
mu = 2mv
v = u/2
= 5 /2
= 2.5 Km/h
Hence, the combined velocity is, v = 2.5 Km/h
