Vector Problems.ppt Vector Problems.ppt

Intro to 2D (or 3D) motion An object moves from position (1,3) m to (4,2) m in 2 s with a constant velocity. Plot the positions Find the velocity vector by using the vector version of kinematics equations Find the magnitude and direction of the velocity Vector Problems.ppt

Problem 6.8 A physics student on Planet Exidor throws a ball that follows the parabolic trajectory shown. The ball’s position is shown at one-second intervals until t = 3 s. At t = 1 s, the ball’s velocity is vx = 2 m/s, vy = 2 m/s Determine the balls velocity vector at t = 0 s, 2 s, and 3 s in unit vector notation. What is the value of g on Planet Exidor? Projectile.ppt

Wall Ball You throw a ball with a speed of 25.0 m/s at an angle of 40.0° above the horizontal toward a wall. The wall is 22.0 m from the release point of the ball. How long does the ball take to reach the wall? How far above the release point does the ball hit the wall? What are the horizontal and vertical components of its velocity when the ball hits the wall? When the ball hits has it passed the highest point in the trajectory? Explain. . Projectile.ppt

Airmail Mary is flying her crop duster at an altitude of 500 m at a speed of 30 m/s. She descends at a constant rate so that she is traveling at 30 m/s in a direction 30° below the horizontal. At an altitude of 250 m, Mary drops a box of candy for her sweetheart Bob. The box lands on Bob's front porch. What was the horizontal distance between Bob's front porch and the point where Mary dropped the candy? What was the velocity of the candy just before it hit the front porch? What was the candy's speed just before it hit the front porch? (Are Bob's parents going to be happy about this?) Projectile.ppt

Rocket III A rocket of mass m takes off at an angle of 45° measured relative to the horizontal. After take-off, the orientation of the rocket remains 45°. The thrust force is Fthrust and it is assumed that the mass and thrust remain unchanged. If there were no gravity, describe the trajectory of the rocket. Is Fthrust greater than, equal too, or less than the weight of the rocket? Describe the trajectory of the rocket. Projectile.ppt

Merry go round You are hanging out by a kid’s park and see a merry go round. You decide to test some physics and do some crazy stuff. The merry go round is 3 m in diameter. As you spin faster and faster on the outside of the merry go round, your acceleration increases. How fast do you have to go so your acceleration is as big as the acceleration due to gravity? Could you actually do this? While the merry go round is still spinning, you move so you are half way towards the center of the merry go round. What is your velocity now? Is your acceleration greater or less than it was before? You move back to the outside of the merry go round and decide to try one last crazy move. You step off the merry go round and get tossed to the ground. Right when you stepped off, what direction was your velocity? Draw a picture to show what you mean.

Angular accelerometer a (rad/s2) An angular accelerometer is attached 0.25m from the center of a disc that can spin. 4 3 2 1 t (s) 1 2 3 4 5 Using the graph (not equations), find the angular velocity w at t = 1, 2, 3, 4, 5 s, assuming at t = 0 s, w = 0. At t = 3 s, what is the tangential velocity and acceleration and the radial acceleration? At t = 5 s, find the same quantities as part b) Velocity.ppt

The fan A spider makes its home on top of a ceiling fan a 1/2 meter from the center of the fan. Bill Nye turns on the fan. The fan takes 2 seconds to go from rest to its final angular speed of 120 revolutions per minute. Amazingly, the spider moves with the fan without slipping. What is the final angular speed of the fan in SI units? What is the final speed of the spider? What is the angular acceleration (assuming that it's constant) of the fan during the first 2 seconds? What is the acceleration of the spider after 1 second? What is the angular displacement of the fan during the first 2 seconds? How far has the spider traveled?

Geosynchronous orbit Geosynchronous orbit (the object stays above the same spot on the Earth) occurs for an object orbiting at radius ~42,000 km. What is the acceleration (due to gravity) experienced by this object? What causes this acceleration? How fast is this object travelling?