# Search results

1. ### Simple Harmonic Motion of a Spring?

Homework Statement If a mass attached to a spring has motion given by the equation X(t) = 5(sin(3pi(t))), what is the equation for the acceleration of the spring? What is the angular speed of the spring,and what is its frequency and period? If the spring has a spring constant of 900 N/m, what...
2. ### Moon orbiting Earth?

Homework Statement Calculate the potential energy and kinetic energy of the moon, as well as it's escape velocity. Give the moon's period and angular speed. Consider the Earth to have a mass of 6 x 10^24 kg, the moon to have a mass of 7 x 10^22 kg, and their center separation distance to be 4 x...
3. ### Gravitational Force in terms of Density?

Homework Statement Express the gravitational force equation in terms of density. Homework Equations F(Gravity) = ((GravitationalConstant)(Mass1)(Mass2))/radius^2 Density = mass/volume The Attempt at a Solution Based on the original equation for gravitational force, there are two masses...
4. ### Moment of Inertia Ratio

Homework Statement What is the ratio of inertia of a 5 meter radius disk to that of a 5 meter radius ring? How would this ratio change if the ring were replaced with a since point mass a distance 5 meters from a pivot point? Homework Equations I = mr2 The Attempt at a Solution The wording in...
5. ### Balancing Beam

Homework Statement In the picture, m1 is 20kg, and the wedge pushes up with a force of 300 N. If the length L1 is 2 meters, solve for m2 and L2. Homework Equations I'm not sure The Attempt at a Solution The picture shows some sort of beam balancing on a fulcrum that is not centered. On the...
6. ### Momentum of a System

Homework Statement Suppose that the momentum of a system is 8 kg m/s. What is the kinetic energy of the system if it has a mass of 10kg? If this system is brought to rest with a constant force in 5 seconds, what is the magnitude of this force? Homework Equations Momentum > p = (m)(v) Kinetic...
7. ### Two objects collide

Homework Statement A 5kg mass moving at 20m/s collides with a stationary 10kg mass. If the 5kg mass comes to rest, how fast will the 10kg mass be moving? M1 = 5kg M2 = 10kg V1 = 20m/s Homework Equations KE = 1/2mv2 The Attempt at a Solution I am fairly confident in this, and that's what...
8. ### Spring Launching a Block

Homework Statement A spring that has a spring constant of 2000 N/m is compressed 5 centimeters from its rest position. If a 2.5kg block is placed on the edge of the spring and then released, what will the block's kinetic energy be once it has completely left the spring? How fast will the block...
9. ### Satellite above the earth

Homework Statement If the earth has a radius of 6 x 10^6 meters, how high above earth's surface does a geosynchronous satellite have to be, if it has a mass of 100kg and gravity acts on the satellite with a force of 4.23 x 10^8 Newtons? What is its linear speed? (Assume the orbit is circular)...
10. ### Ferris Wheel Accelerating

Homework Statement If a Ferris Wheel of radius 25 meters is sped up from a linear speed of 2 meters per second to 3 meters per second, what is its angular acceleration if it takes 5 seconds to do this? How long will it take to complete a complete circle if it continues to accelerate at this...
11. ### Ball Spinning on String

Homework Statement A 5kg ball is swung in a circle of radius .5 meters at a constant speed of 2 meters per second, how much work does the centripetal force do as the ball does once in a circle?If the ball were pushed the same distance as the circumference of the circle with a force equivalent...
12. ### Integration by Parts Twice

Homework Statement Integrate e^3x sin x. Homework Equations uv - Integral(v du) The Attempt at a Solution I am trying to help somebody else with this problem, as I took Calculus a few years ago, but the end is really kicking my butt. I know I'm VERY close, but once I get to the second...
13. ### How long does it take to push this block at an angle?

Homework Statement A 100 kg block is pushed across a level frictionless surface at a 60 degree angle, with a force of 20 newtons. How many seconds does it take to go 100 meters? m = 100kg Mu = 0 Homework Equations F = MA The Attempt at a Solution I sketched out the problem on my paper here...
14. ### Finding Projectiles' Flight Times...

Homework Statement Two projectiles are launched from the ground with initial speeds of 100 meters per second. One is launched straight up, the other at a 30-degree angle. How much time elapses between each's return to ground level? Theta = 30 g = 10 m/s Vinitial = 100 Homework Equations y =...
15. ### What is the Maximum Height of this projectile?

Homework Statement A projectile is launched at 750 meters per second at a 30 degree angle to the horizon. How long is it in the air? How far does it go? What is the maximum height that it reaches? Homework Equations Sin(30)=1/2 Cos(30)=sqrt(3)/2 The Attempt at a Solution This is what I have...
16. ### Why is this force the mgCos while the other is mgSin?

Homework Statement A block is placed on a ramp that is inclined to 60 degrees to the horizon. If the block weighs 10kg and the coefficient of kinetic friction is 0.3, how fast does the block accerlate down the ramp? Homework Equations Theta=60 degrees m=10kg g=10m/s^2 mu=0.3 The Attempt at a...
17. ### A Box is suspended by two strings, what is the tension?

1. The problem statement, all variables, and given/known data Suppose a block is suspended by two strings, one, T1, is anchored at 30 degrees to the horizon, the other, T2, at 60 degrees to the horizon. If the block weighs 100 kg, what is the tension in the two strings? Assume that: The...
18. ### Two identical forces on two different masses...

Here is all the work I have done so far (hopefully it is right). My brain somewhat shuts down when it comes to ratios.