20. A light (essentially massless) rigid rod 2.00-m in length joins two particles with masses 5.00-kg and 2.50-kg at its ends. The combination rotates in the xy plane about a pivot through the center of the rod. 5.00 kg A). origin when the speed of each particle is 5.00 m/s. (include units) Determine the angular momentum of the system about the 200m (2.50kg B) In which direction does the angular momentum vector point?

. A 3.0kg cannon ball is shot from a cannon at a speed of 20m/s. The cannon is oriented50 degrees above the horizontal and the cannon’s barrel is 8.0m above the ground. Youwant to position a mat that will catch the cannon ball.a. Determine how much time the cannon ball will spend in flight.b. Draw a force diagram for three points during the cannon ball’s flight (1) while itis being shot from the cannon, (2) when it is at its maximum height, and (3) whenit is half-way between the maximum height and the mat.c. Determine the horizontal distance from the end of the barrel where you shouldplace the mat so that it will catch the ball.d. How fast is the cannon ball moving just before it hits the mat?

- 46 and R4 = 24 For the following configuration, V,=44 V, R, =2 k2, R2=9, R3 = k2. Vo = ... V R2 R1 R3 R4 السؤال 11 من 18 >« يقوم الانتقال إلى سؤال آخر بحفظ هذا الرد

14

A block attached to a spring with a stiffness of 3.4 N/m. The relaxed length of the spring is 15 cm and its current length is 10 cm. What is the vector force that the spring exerts on the block? A. (-0.34, 0, 0) N                 B. (0.51, 0, 0) N                  C. (-0.51, 0, 0) N D. (0.17, 0, 0) N                  E. (-0.17, 0, 0) N

3. One object dropped from the top of a tall building, and one second later a second object is dropped. Neglecting air resistance, the distance between the falling objects will a. Be constant b. Decrease c. Increase d. Depend on their weight e. Depend on the speed of the plane. Explain your reasoning:

Leo, who has a mass of 72.0 kg, is riding his rollerblades when he collided with the wall. The wall exerted 2895 N of force and brought his body to a stop after 0.370 seconds. What is Leo's velocity before he collided with the wall? 16.9 m/s O 18.9 m/s O 19.4 m/s 14.9 m/s

+y mg +x Surface is frictionless Pulley is massless and frictionless

Q3, Q,4 and Q5

A mass of 95 kg is on a scale in an elevator. The scale reads 830 N for the first 3s after the elevator starts moving. Then it reads 931N for the next 3 seconds. What is the elevator's velocity 6s after starting?