Physics 218: Mechanics

1. Physics 218: Mechanics Instructor: Dr. Tatiana Erukhimova Lecture 10

2. A faulty model rocket moves in the xy-plane (the positive y-direction is vertically upward). The rocket’s acceleration has components ax(t)=t2 and ay(t)=-t, where =2.50 m/s4, =9.00 m/s2, and =1.40 m/s3. At t=0 the rocket is at the origin and has velocity with and • Calculate the velocity and position vectors as functions of time. • What is the maximum height reached by the rocket? • What is the horizontal displacement of the rocket when it returns to y=0?

3. A physics professor did daredevil stunts in his spare time. His last stunt was an attempt to jump across a river on a motorcycle. The takeoff ramp was inclined at 53.00, the river was 40.0 m wide, and the far bank was 15.0 m lower than the top of the ramp. The river itself was 100 m below the ramp. You can ignore air resistance. a) What should his speed have been at the top of the ramp to have just made it to the edge of the far bank? b) If his speed was only half the value found in (a), where did he land?

4. An object is at the point x = L and y = H at the time t=0. It has velocity given by where c1 and c2 are constants. Find the position and acceleration as functions of time.

5. Dynamics Connection between force and motion The concept of force gives us a quantitative description of the interactionbetween two bodies or between a body and its environment

6. Have a great day! Reading: Chapter 5,6 Hw: Chapter 6 problems and exercises