Physics exam 2 part 2

returns more collision energy as rebound energy

A "bouncy" or "lively" ball bounces higher from a rigid, immovable surface than a "dead" ball does because the "bouncy" ball

0.70

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

40000 N/m

A popular playground toy is a flexible seat that has automobile springs attached to it for a little bounce. When a 200 N child sits on the toy, it compresses 5 mm downward. What is the ride's spring constant?

Its total potential energy rises whenever it reorients.

An object is in stable equilibrium only when

10 m

Atmospheric pressure is about 100000 Pa. At what depth in water does this pressure double?

1.11x10^-5m

Bolts work because they act like very strong springs and extend slightly when they are tightened. Suppose a steel bolt has spring constant 1.8x10^8 N/m. How far would it have to stretch in order to provide a force 2000N?

Water pressure at the bottom of the tower is much higher than at the top.

Cities have to use water towers to supply water to because

larger

Compared to planets close to the sun, and based upon Kepler's third law of planetary motion, the length of the year of planets farther out from the sun are

Gravity; Earth

Consider the Moon orbiting the Earth. _______ is the centripetal force for the orbit, and one could therefore measure the mass of the ________ by studying the Moon's orbit.

The weight of the fluid displaced equals the object's weight.

For an object that is floating on a fluid,

move your arm in the direction that the ball is moving.

In a soccer game, someone has kicked the ball so that it is heading right toward your face. You want to slow the ball down with your arm. To execute your plan most effectively you should

the base of support is wider, thus stabilizing the person.

In studying many martial arts, it is necessary to practice efficient and safe postures. One important concept related to how one should stand is that the feet should be reasonably far apart, because

Throwing your keys southward.

Suppose you are spending your weekend on roller skates trying to get momentum from somewhere. Which of the following will give you momentum in the north direction?

greater than your weight

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

accelerating upward.

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

the same.

Suppose you have an aquarium and you notice that you have a solid plastic decoration and a rock of about the same volume but twice as dense, and both are totally submerged in the water. The buoyant force on the plastic object is about ___________as that on the rock.

has a value between 760 kg/m^3 and 910 kg/m^3 .

Suppose you have two containers with liquid in them. One has a density of 760 kg/m^3 and the other has a density of 910 kg /m^3. If an object floats in one container and sinks in the other, the density of the object

40 pounds.

The brake system in most cars makes use of a hydraulic system.This system consists of a fluid filled tube connected at each end to a piston. Assume that the piston attached to the brake pedal has a cross sectional area of one half a square inch and the piston attached to the brake pad has a cross section area of two square inches. When you apply a force of 10 pounds to the piston attached to the brake pedal, the force at the brake pad will be,

45 m/s

The coefficient of restitution for a particular ball is 0.45. If he ball hits a surface traveling at 100 m/s its rebound speed will be

helps the bicycle accelerate inward to complete each turn without skidding.

The curves on bicycle racetracks are steeply banked, so that the inner edge of each curve is much lower than its outer edge. This banking tips the support force that the track exerts on the bicycle wheel toward the center of each turn. That center-directed or centripetal force on the bicycle is important because it

the water leaves the basket moving tangent to the circular path

The spin cycle in your washing machine partially dries clothes by spinning them in a perforated metal basket. Such a process works because

About 40 N

Water weighs about 10 N per liter. A 4.0 kg ball floats on the water's surface. What is the weight of the water being displaced by the ball?

6.672x10^-7N

What is the gravitational force that two 100 kg persons exert on each other when standing 1m apart?

the floor exerts an upward support force on the ball and this force stops the ball's descent and eventually propels it upward.

When you drop a rubber ball on the floor and it bounces, the direction of its velocity reverses because

A marble in the bottom of a spherical bowl.

Which system is in a state of stable equilibrium?

800 liters

You are bored during the summertime when school is not in session and you decide to do an experiment where you compare the properties of water and air. If the density of air is 1.25 kg/m^3 and the density of water is 1000 kg/m^3, what volume of air weighs the same as 1 liter of water?

dividing your mass by 4.

You are playing with your younger cousins and find yourself on all fours, with your hands and feet on four bathroom scales on the level ground. You took a "Physics in Everyday Life" course so you can make a reasonable guess that the reading on each scale is obtained by

Toward the center

You are riding an amusement park ride where you are strapped to the inside of a giant metal wheel that is rotating quite rapidly. Your acceleration is

No because the required force is 36 N.

You are swinging a 2 kg tin can around your head in a perfectly horizontal circle of radius 1 m with a speed of 6 m/s. (This is really not possible but we're saying it almost happens.) If the string can safely exert a force of 30 N will it be able to swing the can?

4 m/s^2

You are swinging a tin can around your head in a perfectly horizontal circle of radius 4 m. (This is really not possible but we're saying it almost happens.) If the speed of the can is 4 m/s what is its acceleration?

8 N

You are swinging a tin can around your head in a perfectly horizontal circle of radius 4 m. (This is really not possible but we're saying it almost happens.) If the speed of the can is 4 m/s and its mass is 2 kg, what inward force is required to keep the can moving in the circle?

the truck's velocity is zero but its acceleration is downward.

You are watching a semi truck bounce up and down on a spring. At the topmost point in the truck's path,

atmospheric pressure cannot support a column of lemonade 20 meters tall.

Your apartment window opens 20 meters (65 feet) above a lemonade stand. Your friend lowers a long plastic tube out the window until its end enters the tank of delicious lemonade far below. She then begins to suck on the other end of the tube in hopes of getting a free drink. To her dismay, she never tastes a drop because

In an elevator not accelerating.

Your apparent weight is equal to your weight