Explore BrainMass


Motion under Gravity

A stone is dropped from the top of a cliff. The splash it makes when striking the water below is heard 3.33 s later. How high is the cliff?

Potential Energy of Configurations

If m1 = 3.12 kg, m2 = 2.74 kg, and m3 = 2.5 kg, to the nearest hundredth of a nJ what is the potential energy of the configuration? (See attached file for full problem description)

Rotating Space Stations

Rotating Space Stations. One problem for human living in outer space is that they are apparently weightless. One way around this problem is to design a space station that spins about its center at a constant rate. This creates "artificial gravity" at the outside of the station. A) If the diameter of the space station is 8

Three objects are positioned along the x axis as follows

Three objects are positioned along the x axis as follows: 4.4 kg at x = +1.1m, 3.7 kg at x = -0.80m, and 2.9 kg at x = -1.6 m. The acceleration due to gravity is the same everywhere. What is the distance from location of the center of gravity to the location of the center of mass for this system A ceiling fan has five blades

box tend to rotate about the center of gravity



When scientists are trying to understand a particular set of phenomena, they often make use of, in a scientific sense, a kind of analogy or mental image of the phenomena in terms of something we are familiar with called: (a) model (b) theory (c) law (d) principle Usually a model is relatively simple and provides a stru

Find the tension on the string while the system is accelerating.

Q1) Block A of mass m1 on a smooth frictionless surface being pulled to the right by the force of gravity on block B with mass m2 by means of the attached string (as shown in the attached image). Assume no friction anywhere in the system. Assuming all units are mks, the force exerted by the gravity that is effective in moving b

Comparing Velocity of Objects Based on Mass; Pendulum

Can anyone please show me how to get started on the attached lab questions? Thanks! Part 2 (also attached) Equipment: A length of string, a compact object which can be tied to the string like a metal washer, a tack, a stopwatch or clock, and a meter or yard stick. Procedure: I. Tie your object to the string and ti

Archimedes' Principle

When you are bathing on a stony beach, why do the stones hurt your feet less when you get in deep water?

Newton's Law of Gravitation

Ocean tides are produced primarily by the gravitational attraction of the Moon. Explain how this attraction gives rise to two tidal "bulges" on opposite sides of the Earth, resulting in two daily high tides and two daily low tides. [hint: Consider the inverse-square relationship of the distance in the gravitational force actin

Motion Under Gravity

The height s (in feet) at the time t (in seconds) of a silver dollar dropped from the top of the Washington monument is s=-16t+555 a.) Find the average velocity on the interval [2,3] b.) FInd the instantaneous velocity when t=2 and when t=3 c.) how long will it take the dollar to hit the ground? d.) Find the velo

Exercise Physiology/Kinesiology/Physics Problem

I am trying to calculate the true weight effects of a supine leg press, standing squat, and bench press in supine. Below is communication between my previous physics professor and myself, but it really didn't answer my question. I guess I want to know if there is mathematical way to get 'true' numbers for the actual weight i

Buoyant Force of Block

A 227-kg block of cement, of density 2.8 x 10^3 kg/m^3, rests on a pedestal in front of the Al Capone Memorial Library. How much did it weigh submerged, while being hauled out of the river (freshwater)?

Specific Gravity

A metal object is hung from a scale and found to weigh 10.0 N. It is then lowered into a tank of water and its "weight," measured while its submerged, is found to be 8.00 N. What is its specific gravity?

Density of Water Over Uranium

The density of uranium is 18.7 x 10^3 kg/m^3. What is it specific gravity? How much more dense than water is uranium?

Centre of Gravity

Locate the centre of gravity of a homogeneous rod bent in the form of a semi-circular arc from A to B. The rod has a weight of 0.5 lb/ft and the radius of the arc is 2 ft.

Newton's Laws - Force

A block of mass m=2.0kg is held in equilibrium on an incline of angle=60 degrees by the horizontal force F. a) determine the value of F b) determine the normal force exerted by the incline on the block (ignore friction).

Static Equillibrium

A trucker needs to weigh a truck that is too long to fit on a platform scale. When the front wheels of the truck are run onto the scale, the scale reads W1. When the rear wheels are run onto the scale so that the front wheels are off, it reads w2. a) Prove that the total weight of the truck is W1+W2. b) Prove that if the truck i

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 gravity

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.

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.)

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