Explore BrainMass


Gravitation: Weightlessness

Astronauts who spend long periods in outer space could be adversely affected by weightlessness. One way to simulate gravity is to shape the spaceship like a cylindrical shell that rotates, with the astronauts walking on the inside surface. Explain how this simulates gravity. Consider (a) how objects fall, (b) the force we

Two problems: Dimensional analysis and Flow of fluid in pipe.

Please see attached file for full problem description. 1. The thickness h of a puddle of water on a waxy surface depends on the density ρ of the liquid, the surface tension γ (SI units: N/m) and another physically which is gravity, g. Use dimensional analysis to find a relationship between the thickness and the other 3 vari

Falling objects Air resistance Gravity Gravitational force

Part 1, each question should be answered separately. 7. Suppose you are in a barrel going over Niagara Falls and during the fall you drop an apple inside the barrel. Would the apple appear to move toward the top of the barrel or toward the bottom, or would it remain stationary within the barrel? 10. (a) Imagine that Charlo

Astrophysics: Friction, Potential Energy, and Kinetic Energy

1. A spring with k = 40.0 N/m is at the base of a frictionless 30.0° inclined plane. A 0.50-kg object is pressed against the spring, compressing it 0.20m from its equilibrium position. The object is then released. If the object is not attached to the spring, how far up the incline does it travel before coming to rest and then


Could you please provide the answers and workings out to the following physics problems. explain exactly how you came up with answer, provide a graph/drawing where needed for better understanding of the answer. Please see attachment. 1. When the net force that acts on a hockey puck is 10 N, the puck accelerates at a rate

Hailstone Physics

Please see attached file for full problem description. A spherical hailstone falls freely from rest under gravity. It initially has radius a. As it falls its volume increases through condensation at a rate equal to times the surface area, where is a constant. (a) Show that after a time t its radius r is equal to a+ t.

Spring Compression

A small block of mass 0.09 kg is placed against a compressed spring at the bottom of a frictionless track that slopes upward at an angle of 40* above the horizontal. The spring has k=640 N/m and negligible mass. When the spring is released, the block travels a maximum distance of 1.8 m along the track before sliding back down. B

Earth, stars, and humanity's search for extraterrestrial intelligence.

Hello I'm of need with patrs A, C & D. Please make them at least 400 words each. I have done B, E & F. but after this help I'll also need to make a 20-25 slide powerponit which I will do. a. Describe the properties of life on Earth. (400 words) b. Examine the possibilities of extraterrestrial life in our solar system. Wh

Ideal spring and simple harmonic motion

To measure the static friction coefficient between a 1.9 kg block and a vertical wall, the setup shown in the drawing is used. A spring (spring constant = 418 N/m) is attached to the block. Someone pushes on the end of the spring in a direction perpendicular to the wall until the block does not slip downward. If the spring i

Acceleration of Gravity/Divergence Theorem

Acceleration of Gravity. See attached file for full problem description. Find the acceleration of gravity g for the following mass distribution. The mass distribution consists of an infinitely long "wire" of radius a running along the z axis, surrounded by empty space then by a hollow cylinder with inner radius b and outer ra

Spacing of Rails/Removal of Heat

1. Segments of 12mt long steel rails are laid end to end when the temperature is -12 degree C. A space is left between rail segments to allow for thermal expansion. a. If they are to just touch when the temp is 33degree C, the spacing is --------- 2. A freezer has a coefficient of performance of 2.40 and can convert 1.80 k

Molecules Escaping Earth's Gravity: Example Problem

Escape velocity near Earth's surface is 11 km/s which means that a particle near Earth's surface traveling faster than about 11 km/s will have enough kinetic energy to completely escape from Earth's gravitational pull. Molecules in the upper atmosphere that are moving faster than this will therefore escape if they do not suffer

Molecules escaping Earth's gravity.

Escape velocity near Earth's surface is 11 km/s which means that a particle near Earth's surface traveling faster than about 11 km/s will have enough kinetic energy to completely escape from Earth's gravitational pull. Molecules in the upper atmosphere that are moving faster than this will therefore escape if they do not suffer

Reaction on point A

In problem 16.3(a), A 60-lb uniform thin panel is placed in a truck with end A resting on a rough hoirzontal surface and end B supported by a smooth vertical surface. Knowing that the deceleration of the truck is 12 ft/s^2, determine the reactions at ends A is a. 70.03 lb b. 60.30 lb c. 90.70 lb d. 80.71 lb

Net Force Gravity

An equilateral triangle L = 11.5 m on a side has an m1= 1.13 kg mass at one corner, a m2 = 2.23 kg mass at another corner and a m3 = 3.39 kg mass at the third corner, as shown in the figure below. Figure is attached. Calculate the magnitude of the net force acting on the 1.13 kg mass. Calculate the direction of the net fo

projectile motion on the surface of the moon

A projectile is launched vertically from the surface of the Moon with an initial speed of 1400 m/s. At what altitude is the projectile's speed three fifths its initial value? Show all your work and calculations and the final answer.

Average net force on the man during landing on the ground

A 75 kg man just before contact with the ground has a speed of 6.4 m/s. (a.) In a stiff-legged landing he comes to a halt in 2.0 ms. What is the average net force that acts on him during this time. (b.) When he bends his knees, he comes to a halt in 0.10 s. What is the average net force now? (c.) During the landing,

Algebra Basics, Equations, and Mathematical Models

Background Information: A simple pendulum, such as a rock hanging from a piece of string or the inside of a grandfather clock, consists of a mass (the rock) and a support (the piece of string). When the mass is moved a small distance away from its equilibrium point (the bottom of the arc), the mass will swing back and forth in

Newton's law of gravitation..

The planet Uranus has a radius of 25,560 km and a surface acceleration due to gravity of 11.1 m/s^2 at its poles. Its moon Miranda (discovered by Kuiper in 1948) is in a circular orbit about Uranus at an altitude of 104,000 km above the planet's surface. Miranda has a mass of 6.6 x 10^19 kg and a radius of 235 km. 1) Calculat

Waves - What is the value of g, the acceleration due to gravity, on Planet X?

Astronauts visiting Planet X have a 2.40 m-long string whose mass is 5.50 g. They tie the string to a support, stretch it horizontally over a pulley 1.60 m away, and hang a 1.80 kg mass on the free end. Then the astronauts begin to excite standing waves on the string. Their data show that standing waves exist at frequencies of 6

Rocket Propulsion

A single-stage rocket is fired from rest from a deep-space platform, where gravity is negligible. If the rocket burns its fuel in a time of 50.0 s and the relative speed of the exhaust gas is 2100 m/s, what must the mass ratio mo/m be for a final speed v of 8.00 km/s (about equal to the orbital speed of an earth satellite)?

Free Fall

Determined to test the law of gravity for himself, a student walks off a skyscraper 180 m high, stopwatch in hand, and starts his free fall (zero initial velocity). Five seconds later, Superman arrives at the scene and dives off the roof to save the student. 1) Superman leaves the roof with an initial speed Vo that he produce

Knowledge of Molecular Speeds and of Gravity

Consider the atmosphere of the earth; and the moon. Using your knowledge of molecular speeds and of gravity, find the following and comment about your results, etc.. Calculate the escape velocity of a mass at the surface of the earth. The T of the earth's upper atmosphere is actually pretty high; say 1000 K. Find the probability

Circular Motion with Centripetal Acceleration

I need some help with circular motion physics questions: 1. Young David who slew Goliath experimented with slings before tackling the giant. He found that with a sling of length .598 m, he could develop a rotation rate of 8.04 rev/s in his weapon. If he increased the length to .892 m, he could revolve the sling only 5.99 time

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?