Egemen Aksu
2445351
HOMEWORK 6
Due Date: 24.04.2023 (23.59)
Assistant: Elif Ceren Ekinci (ceren.ekinci@metu.edu.tr)
You should submit your homework on its due time to OdtuClass. No extensions will
be given beyond the due date.
You must write your answers in the boxes.
Round your answers to 2 decimals.
Problem 1:
A rocket of 8000 kg is travelling upwards while subjected to a constant thrust force of T=100 kN.
When it is moving with 10 m/s, it starts to rotate clockwise at 0.6 rev/s. If aerodynamic forces are
neglected, determine the velocity of the rocket 3s after the rotation starts.
Solution:
Final Answer:
18.09 m/s
Problem 2:
The total external force on a 2 kg object is ∑ 𝐹 = 2 ⋅ 𝑡 i +4 j in N, where t is time in seconds. At time
𝑡 = 0 , its position and velocity are 𝑟 = 0 , 𝑣 = 0 .
a)Use Newton’s second law to determine the object’s position r and velocity v as a function of time.
Final Answer:
v = t²/2i + 2tj r = t³/6i + t²j
b)By integrating 𝑟 × ∑ 𝐹 with respect to time, determine the angular impulse from 𝑡 = 0 to 𝑡 =
6𝑠.
Final Answer:
I = -432k kg*m²/s
c)Use your results from part (a) to determine the change in the object’s angular momentum from
𝑡 = 0 to 𝑡 = 6 𝑠 .
Solution:
Final Answer:
Delta L = -432k kg*m²/s