# Search results

1. ### Radial acceleration, help needed

Homework Statement A car at the Indianapolis 500 accelerates uniformly from the pit area, going from rest to 320km/h in a semicircular arc with a radius of 200 m. Determine the tangential and radial acceleration of the car when it is halfway through the arc, assuming constant tangential...
2. ### Rounded top hill question

Homework Statement a 1000kg sports car moving at 20m/s crosses the round top of a hill (radius of 100 m) . Determine the normal force on the car Homework Equations Newton’s second law F=ma The Attempt at a Solution I figured out the centripetal acceleration Ac= v^2/r = 4 m/s^2 My attempt...
3. ### Car on a bank problem need help ?!!

Homework Statement If a curve with a tedious of 80m is perfectly banked for a car traveling 70km/h, what must be the coefficient of static friction for a car not to skid when traveling at 90 km/h ? Homework Equations Newton’s second law F=ma The Attempt at a Solution To find the angle of the...
4. ### Gravitational problem, spacecraft orbital period

Homework Statement I need help getting started with this problem At what altitude above the surface of the Moon must a lunar module orbit in order to complete each orbit in 1 h 49 min 39 s? Homework Equations g= Gm/r^2 ? The Attempt at a Solution Not quite sure how to start or anything , any...
5. ### Projectile problem on Pluto

Homework Statement An astronaut throws a rock at 12 m/s at an angle of 25° above horizontal from a height of 3.25 m above the surface. How far horizontally does the rock travel before hitting the surface of Pluto? Pluto has a mass of 1.27 E22 kg And a radius of 1.14E6 m Homework Equations...
6. ### Roller coaster problem involving velocity

Homework Statement A roller coaster reaches the top of the steepest hill with a speed of 7.0 km/h. It then descends the hill, which is at an average angle of 43° below horizontal and is 46.0 m long. What will its speed be when it reaches the bottom? Assume the coefficient of kinetic Friction...
7. ### Vectors problem

Homework Statement I’m working on a problem that requires adding 3 vectors . And while I was following the book, it said to find the angle to divide the y over the x components of the resistant , and showed the angle to be -1.25 but then follow d to change to -51 . How did it change ? The book...
8. ### Find the force to push a book sideways on a table

Homework Statement Place a book flat on a table and press down on it with your hand. Now suppose the hand-book and table- book values of are 0.50 and 0.40, respectively; the book's mass is 0.90 kg and your downward push on it is 10 N. How much horizontal force is needed to keep the book moving...
9. ### Find minimum stopping distance

Homework Statement A crate is being transported on a flatbed truck. The coefficient of static friction between the crate and the bed is 0.470. What is the minimum stopping distance if the truck, traveling at 70 km/h, is to decelerate uniformly and the crate is not to slide forward on the bed...
10. ### Solve for the tension in a rope pulling a box

Homework Statement A worker is going to attempt to pull a 90-kg box across a level floor by a rope that makes an angle of 35° with the floor. The tension in the rope is gradually increased until the box just starts to move. If the coefficient of kinetic friction is 0.36 and the coefficient of...
11. ### Determine the elevator's acceleration

Homework Statement An 82 kg man inside a 40-kg dumb-waiter pulls down on the rope. At that moment the scale on which he is standing reads 209 N. Determine the elevator's acceleration. Homework Equations F=ma The Attempt at a Solution I know the acceleration is 0.152 m/s^2 upwards , I need...