# Recent content by pech0706

1. ### Angle at which a ladder begins to slip

Homework Statement Consider the ladder in the figure. Assume there is friction between the verticle wall and the ladder, with the coeffecient of static friction=0.30. Find the angle at which the ladder just begins to slip. Homework Equations...
2. ### Force exerted by 2 supports on the plank

Homework Statement Suppose a crate of mass 7.5 kg is placed on the plank in the figure below, at a distance of 3.9m from the left end. Find the forces exerted by the 2 supports on the plank. Homework Equations Torque=radius*force The Attempt at a Solution I've used the tourque...
3. ### Spring compression as a launcher and velocity at a certain point

i used v2=gR to find the v at B. then i used that in the energy conservation equation and got vo to be 5.85. and i know that the Vo=Vc, so do those numbers look right?
4. ### Velocity leaving a cannon, hitting landing cushion, and acceleration experienced

alright, using 3m as the range for the range equation i got an initial velocity of 5.8m/s, but that got me an even smaller acceleration.
5. ### Spring compression as a launcher and velocity at a certain point

Homework Statement A game uses a spring launcher to shoot a puck with mass of 0.5kg along a frictionless track as shown in the diagram. The spring has a k value of 600 N/m. By how much does the spring need to be compressed to launch the puck and have it go around the inside of the loop...
6. ### Velocity leaving a cannon, hitting landing cushion, and acceleration experienced

Homework Statement An 80 kg stuntman is shot from a cannon at a circus. The cannon is 3m in length and angled at 35 degrees above the level floor. The landing cusion is 30m away from the cannon. What velocity will the stuntman have 1)when he leaves the cannon and 2)when he first hits the...
7. ### Car on banked turn, with reversed banking angle

Homework Statement Consider the problem of a car traveling along a banked turn. Sometimes roads have a "reversed" banking angle. That is the road is tilted "away" from the center of curvature of the road. The coefficient of static friction between the tires and the road is \mus=0.50, the...
8. ### Coefficient of Friction between tires and racetrack

Homework Statement Jeff Gordon (a race-car driver) discovers that he can accelerate at 4.0m/s2 without spinning his tires, but if he tries to accelerate more rapidly he always "burns rubber." Find the coefficient of friction between his tires and the road. Assume the force from the engine is...
9. ### Finding the Normal Force between two Crates

Okay so the forces acting on the small crate are a frictional force in the negative x direction wich is what I calculated out to be be 75.537. There is also a force from the larger mass pushing into the smaller crate... and is there also the force of the crates' velocities?
10. ### Finding the Normal Force between two Crates

Alright, I did the math based on the small great, and I got the right answer (basically) Ffriction=the coefficient of friction*the normal force. Ffriction=(0.35)(215.82) Ffriction=75.537 That's a lot better. I don't understand why you use the small crate to solve this problem though.
11. ### Finding the Normal Force between two Crates

Fgrav of m1=(45kg)(9.81m/s2)=441.45N Fgrav of m2=(22kg)(9.81m/s2)=215.82N Normal Force on both grates=441.45N+215.82=657.27N That was my original/best guess on how to do it, but I am WAY off.
12. ### Finding the Normal Force between two Crates

Homework Statement Your moving company runs out of rope and hand trucks, so you are forced to push two crates along the floor. The crates are moveing at constant velocity, their masses are m1=45kg and m2=22kg, and the coefficient of kinetic friction between both crates and the floor are 0.35...
13. ### Coefficient of kinetic Friction given velocity and distance.

So, basically that means the total force acting on the car is the velocity and the frictional force. After ignoring the mass though, I'm still stuck. I don't know how to find the frictional force or the coefficent of friciton when ignoring mass.
14. ### Coefficient of kinetic Friction given velocity and distance.

Homework Statement A car is moving with a velocity of 20m/s when the brakes are applied and the wheels lock (stop spinning), The car then slides to a stop in 40m. FInd the coefficient of kinitic friction between the tires and the road. Homework Equations F=ma Ffriction=coefficient...