2. Draw the free-body diagram for the system with the assum mption stated above.

題組內容

C. As shown in Fig. 7, a 2 m long, 30 kg slender bar is constrained to move in the illustrated guide. Point B is able to mo ove in the vertical direction n, and A moves in the horizontal direction. At the instant shown, the spring is uncompressed, and the speed of B is 2 mis downward. The vertical guide provides a constraint force of 100N for B, and the spring constant is k = 100 N/m.

B. You are requested to participate in a court case as an expert witness. As illustrated in Fig. 6, a spacecraft is known to have unfortunately exploded into three pieces, A, B, and C. ma - 1000 kg, ma = 500 kg, and mc = 500 kg. Telemetry data showed that the positions of the satellitc with respect to a know wn reference ce position O at a particular tim ime were Rwo = (400 i - 1000 ) m, Ro = 1000 j m, and Reo = (800 i + 1000 j) m. The respective velocities were V, = -500j m/s, VB = (-4001 + 500) m/s, and Vc = (400i + 500) m/s. The engineer of the spacecraft company claims that a single explosion caused the described configuration, whereas the lawyer representing the insurance ce company contends that at least two separate explosions were responsible. Who is correct? (You have to describe detailed reasons and calculation results to support your answer. O point will be given if no explanation is provided.)

題組內容

2. Draw the free-body diagram for the system with the assum mption stated above.

相關申論題

相關試卷