Exam 3: Mechanical Objects, Part 1

You're riding on a pogo stick-a vertical stick with a spring at the bottom and foot pads on which you stand. You're holding the top of the stick tightly in your hands and you and the stick are bouncing up and down on its spring. As you land after one particularly high bounce, the spring becomes more and more tightly compressed. When the spring is at half its maximum compression, your velocity is

Suppose a soap box car is coasting on a track (no motor; no brake), moving from left to right, and part of the track is shown below. Friction /air resistance is not present and the car is almost stopped, barely moving at point E. -Please identify points of maximum and minimum potential energy, if any.

You are swinging a tin can around your head in a perfectly horizontal circle and its acceleration is 32 m/s². If its speed is 4 m/s what is the value of the radius of its circular path?

You go to an amusement park and, being in a physics class, you have connections. The management lets you stand on a scale as you ride a Ferris Wheel that rotates fairly rapidly. You will notice the lowest reading on the scale

Suppose a soap box car is coasting on a track (no motor; no brake), moving from left to right, and part of the track is shown below. Friction /air resistance is present and the car comes to a stop at point E. -Please identify points of maximum and minimum potential energy, if any.

Imagine that you are able to go on a fishing trip that you have always wanted to. Your friend gets a bite that exerts a force of about 50N on the pole and it bends by a certain amount. Now you have a pole identical to your friends and you get a hit that bends the pole about twice as much. You can estimate that the force on your pole is about

You have watched one too many old cartoons and decide to drive around town with a giant spring that is 4 m long and attached to the front of your car. You decide to help a semi truck that is stuck and try to push them with your car. You take a running start, and when you contact the truck the spring in your car compresses 3 m. During which portion of the compression did you do the least work on the spring?

A ball hits a wall going 10 m/s, and bounces off going 7 m/s. The coefficient of restitution is

Suppose you are standing on a bathroom scale when you are flying in a jet airplane. For a moment the scale reads less than your actual weight. During that moment, it's exerting an upward force on you that is

Suppose that a frantic weather reporter is covering a live tornado. It is in the mature stage just ripping right along and the reporter exclaims that "Wood, metal and all kinds of debris are being thrown directly outward from the edge the funnel." From a physics point of view (circular motion!) please comment on the accuracy of the reporter's statement.

A person is swinging a tin can around in a vertical circle at a constant speed. Please identify the points, if any, of -maximum/ minimum potential energy

Some engineers have suggested that we can simulate gravity in outer space by having a circular rotating space station where persons feel an outward - directed fictitious force due to the rotation of the station. The reason they feel such a force is because

You are flying on an airplane and you notice that a ball of aluminum foil from lunch starts to roll to the left. From the motion of the foil ball you can conclude that the plane is

You are watching a semi truck bounce up and down on a spring. (Yep it's a toy!) At the topmost point in the truck's path,

Cars are designed so that their bodies buckle (permanently deform) when they are in an accident. How does the buckling make the car safer by not allowing it to recoil (bounce) so much?

When you throw a tennis ball against the floor at an angle,

Which system is in a state of stable equilibrium?

Assuming there is nothing wrong with your bathroom scale, discuss two ways in which you could get a false reading when weighing yourself, with only you touching the top of the scale (and nothing else) and another surface touching its bottom.

When a baseball player hits a ball with the bat, the bat can undergo many different types of changes. Please discuss three different types of effects that contact with the ball has on the bat.

You thoughtfully set a 1 kg box on top of a loaf of bread and the loaf compresses by 15 cm. Thinking of the bread as a spring, its spring constant is