Share
Explore BrainMass

Classical Mechanics

Mixed Algebra & Calculus Problems

(See attached files for full problem descriptions) --- Problem Set 1 1) If 2x + y = 3 and x - y = 3: a) What is x? A) 1 B) 2 C) 3 D) 0 E)-1 b) What is y? A) 1 B) 2 C) 3 D) 0 E)-1 2) If you walk 3 miles in one hour and then 4 miles in two hours, what is your average speed for the entire trip? (in mph

Energy of pulse on a string

Here is a string problem I'm having much trouble with. An explanation would be greatly appreciated. It's written much more clearly on the attachment, so please go there first!!! Here it is, Consider a string under a tension T, mass density ρ with a pulse ξ(x,t) = ξ_0^ (-(x-ct)^2/a^2) . propag

Oscillation and Pendulum Motion

A mass on a string of unknown length oscillates as a pendulum with a period of 4.0 (s). Parts a to d are independent questions, each referring to the initial situation. What is the period if: a. The mass is doubled? in seconds b. The string length is doubled? in seconds c. The string length is halved? in seconds d. The ampli

Impulse with Constant Velocity

An 79.1 kg astronaut is working on the engines of his ship, which is drifting through space with a constant velocity. The astronaut, wishing to get a better view of the Universe, pushes against the ship and much later finds himself 30.4 m behind the ship. Without a thruster, the only way to return to the ship is to throw his 0.5

Kinetic friction

If an object slides directly down an inclined place, at a constant velocity of 6 m/s, how large is the coefficient of kinetic friction if the plane make an angle of 25 degrees with the horizontal?

Solve: Distance and Time

Hi, I need some assistance with the following questions: Question: At the average rate of 15 m/s^2. How much time does it take for the complete increase in speed? a. 0.25 s b. 4.0 s c. 0.0577 s d. 17.3 s e. 8.0 s Question: A car traveling 20 m/s is able to stop in a distance d. Assuming the same braking force, what

A safe

A safe with a mass of 150kg is at rest on the floor. what is the minimum horizontal force needed to move the safe if the coefficent of static friction between the safe and the floor is 0.3? a.441n b. 51n c.501n d.41n

Multiple choice question on elongation of wire

The weight that will cause a wire of diameter d to stretch a given distance, for a fixed length of wire, is a. proportional to d^2 b. independant of d c. proportional to d d. independant of what the lengthof wire is

Pulley

What is a pulley? where is it used?

Force and Shear Moduli

Two metal plates are held together by two steel rivets, each of diameter 0.20 cm and length 1.0 cm. How much force must be applied parallel to the plates to shear off both rivets? The shear modulus of steel is 8.2 x 10^10.

Solving an Elasticity Problem

A phone line 2.0 m in diameter and 0.5 km long is stretched 0.5 m by a force of 4000 N. Determine: 1. the stress on the wire 2. the strain on the wire 3.Young's modulus for the cable material.

Speed of a Rolling Hoop

A hoop of radius 0.5 m and a mass of 0.2kg is released from rest and allowed to roll down an inclined plane. How fast is it moving after being dropped from a vertical distance of 3m? a. 5.4 m/s b. 3.8 m/s c. 7.7 m/s d. 2.2 m/s

Linear Momentum and Collisions

A 16 g rifle bullet traveling 150 m/s buries itself in a 4.0 kg pendulum hanging on a 3.3 m long string, which makes the pendulum swing upward in an arc. Determine the horizontal component of the pendulum's displacement.

Physics: Springs and Compression

1. A spring is compressed 10 cm by pushing a body against it. When released the spring pushes the body towards another identical spring. The body must slide over a rough floor in order to reach the second spring. When it makes contact the body compresses the opposite spring by 8 cm. Once again the body is forced back over the ro

Finding the Center of Mass of a Rod

A 3.0 kg rod of length 5.0 m has at opposite ends point masses of 4.0 kg and 6.0 kg(a) Will the center of mass of this system be (1) nearer to the 4.0 kg mass, (2) nearer to the 6.0 kg mass, or (3) at the center of the rod? Why? (b) Where is the center of mass of the system?

Finding Tension

A 271kg log is being pulled up a ramp by means of a rope that is parallel to the surface of the ramp. The ramp is inclined at 24 degrees with respect to the horizontal. The coefficient of knetic friction between the log and the ramp is 0.840 and the log has an acceleration of .900. Find the tension.

Springs

Question: When an object weighing 50 N is hung from a vertical spring, it stretches 20 cm. Calculate the spring's elastic constant. If the 50 N load were replaced with a 80 N weight, how far would the spring stretch?

Falling Objects

A first stone is dropped from the roof of a building. 2.50 s after that, a second stone is thrown straight down with an initial speed of 30.0 m/s, and it is observed that the two stones land at the same time. (a) How long did it take the first stone to reach the ground? (b) How high is the building? (c) What are the spe

Kinematics in One Dimension

An automobile traveling v = 85 km/h overtakes a L = 1.15 km long train traveling in the same direction on a track parallel to the road. If the train's speed is 80 km/h, how long does it take the car to pass it (min), and how far will the car have traveled in this time? (km) What are the results if the car and train are travel

Tension on a bridge cable

A knight in armour on a horse leaves the castle. His squire has mistakenly lowered the drawbridge 20 degrees below the horizontal. The knight and his horse stop when their combined center of mass are 1 metre from the end of the bridge. The uniform bridge is 8 metres long and has a mass of 2000 kg. The lift cable is attached t

Damped Egg on a Spring

Please do not place your response in a .pdf or .cdx format, but Word documents are okay. Thanks! Here's the actual problem: A 50.0-g hard-boiled egg moves on the end of a spring with force constant k=25.0 N/m. It is released with an amplitude 0.300 m. A damping force F_x=-bv acts on the egg. After it oscillates for 5.00 s,

Analyzing Simple Harmonic Motion

The applet at the following site (http://mp.pearsoncmg.com/probhtml/ActivePhysics/pt1a/Media/Vibrations/PositionGraphsEqns/Sim4.html) shows two masses on springs, each accompanied by a graph of its position versus time. A) What is an expression for x_1 (t), the position of mass I as a function of time? Assume that position i

Speed of Bullet

A 5.00-g bullet is shot through a 1.00-kg wood block suspended on a string 2.000 m long. The center of mass of the block rises a distance of 0.45 cm.Find the speed of the bullet as it emerges from the block if its initial speed is 450 m/s.

Maximum Angle of Incline

A spherical shell starts from rest and rolls down an incline. The coefficient of static friction between the shell and incline is (Us=.2). What is the maximum angle of incline such that the shell will roll without slippage?

Sliding Plates

Each of the three plates has a mass of 10kg. If the coefficients of static and kinetic friction at each surface of contact are us = 0.3 and uk = 0.2 respectively, determine the acceleration of each plate when the three horizontal forces are applied. See attachment for diagram.