A scientist measures the growth of a bamboo plant over time. The table above shows the results. What is the best interference fo
r the height of the plant after 45 hours?
A. 2.40 cm
B. 2.25 cm
C. 2.55 cm
D. 2.10 cm
A. 2.40 cm
B. 2.25 cm
C. 2.55 cm
D. 2.10 cm
1 answer:
You might be interested in
Answer:
6.25 m/s
Explanation:
mass of man (m1) = 80 kg
mass of boy (m2) = 20 kg
mass of man and boy after collision (m12)= 20 + 80 = 100 kg
velocity of man and boy after collision (v) = 2.5 m/s
angle θ = 60 °
How fast was the boy moving just before the collision ?
- From the diagram attached, the first image shows the man and the boys motion while the second diagram shows their motion rearranged to form a triangle. With the momentum of the man and the boy forming the sides of the triangle.
- M₁₂ = total momentum after collision = m12 x v = 100 x 2.5 = 250
- Mboy = momentum of the boy before collision = m2 x Velocity of boy
- Mman = momentum of the man before collision = m1 x velocity of man
- from the triangle, cos θ =
cos 60 =
Mboy = 250 x cos 60 = 125
- recall that momentum of the boy (Mboy) also = m2 x Velocity of boy
therefore
125 = 20 x velocity of boy
velocity of boy = 125 / 20 = 6.25 m/s