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# Gravity

### Flow Rate Through a Water Hose

Two children, Ferdinand and Isabella, are playing with a water hose on a sunny summer day. Isabella is holding the hose in her hand 1.0 meters above the ground and is trying to spray Ferdinand, who is standing 10.0 meters away. To increase the range of the water, Isabella places her thumb on the hose hole and partially covers it

### Equilibrium and Center of Gravity

A 170cm tall person lies on a light (massless) board which is supported by two scales, one under the feet and one beneath the top of the head. The two scales read, respectively, 31.6kg and 35.1 kg. Where is the center of gravity of this person?

### Fluid Statics

The specific gravity of ice is .917, whereas that for seawater is 1.025. What fraction of an iceberg is above the surface of the water? *note- if possible, please explain this in the simplest way you can- i'm not naturally a science kinda gal! Thanks :)

### Center of mass of a cemi-circular thin rod.

Locate center of gravity (x) of homogenous rod bent in the form of a semicircular arc. Rod has a weight per unit length of 0.5 lb/ft. radius of arc is 2ft.

### Coefficient of static friction

Force of static friction between any two surfaces is given by: Ff=Us*N How do you find the mass of the coin(m), gravity(g) (9.8m/sec2) and the angle (30) the flat surface makes with the table; Ff=m.g.sin0 and N=m.g.cos0 using the above expressions of Ff and N and the definition of the force of static fricition,show that the co

### Air pressure, gauge pressure

Hi. Can someone please walk me through how to do the following problem? Suppose that when you ride on your 7.70-kg bike the weight of you and the bike is supported equally by the two tires. If the gauge pressure in the tires is 70.5 lb/in^2 and the area of contact between each tire and the road is 7.13 cm^2, what is your weig

### Equilibrium between gravity and electrostatic field

Two dust particles each of mass 13 ug (10^-6) are floating on a gentle stream of air. what (equal) positive charge would each dust particle have to carry in order that their electrostatic repulsion should exactly balance their gravitational attraction? What is the electrostatic potential energy of the two dust particles each

### Motion in the y direction

I don't know how to approach this problem because I don't think that it will be a trajectory problem since the ball is going straight up in the air. Can you help? (See attachment.)

### Equilibrium and Gravity

In Figure 13-5 (not to scale), a package of mass m hangs from a short cord that is tied to the wall via cord 1 and to the ceiling via cord 2. Cord 1 is at an angle of = 40° with the horizontal. Cord 2 is at angle (theta). a. For what value of theta is the tension in cord 2 minimized?(in degrees) b. In terms of mg, what is

### Gravity field of a hollow planet

A uniform, spherical planet has a spherical space at its center. The radius of the surface of the planet is Rp= 8.9E7 m (8.9 x 10^7 m). The radius of the central hollow space is Rh = 6.2E5 m. The total mass of the planet is M= 7.5E28 kg. The distance from the center to three designated points are: Point a is distance Ra= 9

### Calculating the Force Gravity

Question: A steel block has a volume of 0.08 m^3 and a density of 7,840 kg/m^3, what is the force (fo) gravity acting on the block (the weight) in water? A. 5362.56N B. 6150.64N C. 6700.56N D. 7600.18N

### Find Gravity Field of a Planet and Orbital Speed of a Spacecraft

A cloud of dust in space originally occupies volume V= 3.5 x 10^26 m^3 whose average density D= .0085 kg/m^3. Over many billions of years it contracts to form a uniform spherical planet with radius r=5.5 x 10^6 m. Part a. Find the gravity field, g, at the surface of the planet. Part b. Find the orbital speed v, of a spacecraf

### Newton's universal law of gravity

Accodting to Newton's universal law of gravity, if the separation between to bodies is increased by a factor of three, the gravitational pull each has on the other will be X by a factor of Y ?

### "From the earth to the moon", Jules Verne Physics Problem

In his novel "From the earth to the moon", Jules Verne imagined that astronauts inside a space ship would walk on the floor of the cabin when the force exerted on the ship by the earth was greater than the force exerted by the moon. When the force exerted by the moon was greater he thought the astronauts would walk on the ceili

### Apparent Weightlessness and artificial gravity: moon's motion

The moon orbits the earth at a distance of 3.85 x 10^8 m. Assume that this distance is between the centers of the earth and the moon and that the mass of the earth is 5.98 x 10^24 kg. Find the period for the moon's motion around the earth. Express the answer in days and compare it to the length of a month.

### Working with gravitation - three problems

1. Show by algebraically reasoning that your gravitation acceleration towards an object of mass M a distance d away is a=GM/d^2 and therefore doesn't depend on your mass. 2. Can a satellite coast in a stable orbit in a plan that doesn't intersect the earth center? Defend your answer. (Include 1 or more diagrams) 3. Stude

### Constructing a corbeled arch

Four bricks are to be stacked at the edge of a table, each brick overhanging the one below it, so that the top brick extends as far as possible beyond the edge of the table. (a) To achieve this, show that successive bricks must extend no more than (starting at the top brick)1/2, 1/4, 1/6, and 1/8 of their length beyond the one b

### Coplanar Forces acting on an object at different magnitudes and directions.

Three coplanar forces act on a 75000.0 kg object in outer space, where there is no gravity: 14.2 kN directed at 357°, 25.6 kN at 138°, and 16.4 kN at 255°. What is the magnitude and direction of the acceleration? If the object has an initial velocity of 17.5 miles/h directed at 58.6° in the same plane as all three

### system center of mass and gravity point to produce zero field

SEE ATTACHMENT #1 for a diagram showing parameters. Consider the earth, mass M= 5.98 E 24 kg, and the moon, mass m= 7.35 E 22 kg, as a system with distance d= 3.84 E 8 m between their centers. Find the distance between the c.m. (center of mass) of the system, and the point where the gravity field of the earth cancels that

### thin rod with evenly spaced masses rotates in space

SEE ATTACHMENT #1 for a diagam showing parameters and basic equations (1) and (2). A thin rod of negligible mass is 6 meters long. Five equal masses, each M= 2.5 kg, are attached to the rod evenly spaced 1.2 meters apart. In gravity free space, the system rotates about the center of the rod, completing 15 revolutions every 6

### Understanding common observations

A) Very often a sinking ship will turn over as it becomes immersed in water. Why? B) Is it true that a floating object will only be in stable equilibrium if its centre of buoyancy lies above its centre of gravity? C) Why should one take short steps rather than long ones when walking on ice?

### Pendulum's period on the earth to period on a moon

A simple pendulum, length L, completes 12 oscillations in 30 seconds here on the earth where g= 9.8 nt/kg. The same length pendulum on a certain moon of Jupiter, completes 18 oscillations in 54 seconds. a.) Find the acceleration of gravity, g1, on that moon. b.) Find the weight on the surface of that moon, of a person w

### Gravity Work required to move a mass radially outward

See attachment #1 for diagram showing parameters. A uniform spherical planet has mass M= 8.5 E 25 kg and radius R= 7.5 E 6 m. A hole is drilled from the surface to mass m= 360 kg at an initial position r1= 2.5 E 6 m from the center. PART a. Find the initial gravity force F that the planet exerts on mass m. PART b. F

### Gravity field at points interior to a uniform spherical shell

Show that the gravity field of a spherical shell of matter is zero at all points within it.

### Gravity forces and fields between two masses (earth & spacecraft

See attached file. Assume the earth to be a uniform spherical planet, mass M= (5.98 E 24) kg. (The number, in scientific notation, means '5.98 times 10 to the 24') The earth's radius is R= (6.37 E 6) m. Part a. Find the force of gravity between the earth and a spacecraft whose mass is m= 36000 kg, which is at height h=

### Physics: Venturi meter readings sphere density.

1a) A venturi meter has 0.02556m^3 of flow per second through its 45mm dia throat.If the pipe is 58mm in diameter,what will the differential reading of mercury across it be? b)A metal sphere 60mm in dia is submerged in oil with a relative density of 0.9.Need to find the density of the sphere.There is a downward force of 8.31N wh

### Venturi meter readings sphere density.

1a) A venturi meter has 0.02556m^3 of flow per second through its 45mm dia throat.If the pipe is 58mm in diameter,what will the differential reading of mercury across it be? b)A metal sphere 60mm in dia is submerged in oil with a relative density of 0.9.Need to find the density of the sphere.There i

### Center of Gravity: Example Problem

A lunch tray is being held in one hand. The mass of the tray itself is .200 kg, and its center of gravity is located at its geometrical center. on the tray is a 1.00 kg plate of food and a .250kg cup of coffee. obtain the force T exerted by the thumb and force F exerted by the four fingers. Both forces act perpendicular to the t

### Cube in water: density, volume and force calculations

Imagine that you have a solid cube composed of Material X. You put the cube into a beaker filled with water. The cube sinks to the bottom of the beaker and sits there, at rest, on the bottom. Which of the following statements are true? (Give ALL correct answers: B, AC, BCD, ... , or None) A) The buoyant force on the cub

### Block sliding on a sphere

A small block slides from rest from the top of a frictionless sphere of radius R. How far below the top of the sphere does the block lose contact with the sphere? The sphere does not move. Gravity is acting on the block.