# Search results

1. ### Finding the Mass of an Atom

Homework Statement A mass spectrometer analyzes and gives data for a beam of doubly ionized atoms. The values are q = 2(1.60 x 10^-19 C), B = 5.0 x 10^-2 T, r = 0.120 m, and V = 3442.9 V. Find the mass of one of these atoms. Homework Equations B^2*q*r^2 / 2*v The Attempt at a...
2. ### Finding the force of magnetic field lines

Homework Statement A wire carrying 15 A of current has a length of 17 cm in a magnetic field of 0.80 T. The force on a current-carrying wire in a uniform magnetic field can be found using the equation F = BIL sin θ. Find the force on the wire for each of the following angles between the wire...
3. ### How to find the current and equivalent resistance in a parallel circuit

Homework Statement Three 16 ohm resistors are connected in parallel and placed across a 34 V battery. (a) What is the equivalent resistance of the parallel circuit? (b) What is the current delivered by the battery? Homework Equations (a) (1/equivalent resistance) =...
4. ### How do you find the direction and magnitude from a nucleus?

Homework Statement The nucleus of an atom has a charge of 65 protons. (a) What are the direction and magnitude of the electric field at 4.9 x 10^-10 m from the nucleus? (b) What are the direction and magnitude of the force exerted on an electron located at this distance? Homework...
5. ### How to find the force of particles

r stands for culomb's law(?), and i'm not quite sure about the others..
6. ### How to find the force of particles

Homework Statement A positive and a negative charge, each of magnitude 1.9 multiplied by 10^-5 C, are separated by a distance of 11 cm. Find the force on each of the particles. Homework Equations F = kq^2/r^2 r = sqrt(kq1q2/F) The Attempt at a Solution i'm not sure which...

2.2 kg
8. ### How to find the amount of work done on an object

m = 1.10 or 7.9 g = 2200 mg = 2,200,000
9. ### How to find the amount of work done on an object

Homework Statement A student librarian picks up a 2.2 kg book from the floor to a height of 1.10 m. He carries the book 7.9 m to the stacks and places the book on a shelf that is 0.35 m above the floor. How much work does he do on the book? Homework Equations...
10. ### How do you find speed?

oops, double posted. sorry. & that was correct, thanks!
11. ### How do you find speed?

Homework Statement A 0.105-kg hockey puck moving at 20 m/s is caught and held by a 77-kg goalie at rest. With what speed does the goalie slide on the ice? Homework Equations (Initial puck speed)(Puck mass) = (combined mass)*(final goalie velocity) The Attempt at a Solution...
12. ### Two objects colliding & sticking together, what is their final speed?

Homework Statement Two freight cars, each with a mass of 2.5 multiplied by 10^5 kg, collide and stick together. One was initially moving at 3.4 m/s and the other was at rest. What is their final speed? Homework Equations m(vf-vi) The Attempt at a Solution (2.5*10^5)(0-3.4)=...
13. ### Magnitude, Direction of Momentum, & Velocity

Homework Statement A compact car, mass 775 kg, is moving at 1.00 multiplied by 10^2 km/h toward the east. (a) Find the magnitude and direction of its momentum. (b) A second car, mass 2125 kg, has the same momentum. What is its velocity? (in km/h) Homework Equations The...
14. ### Magnitude & Direction

Homework Statement An animal-rescue plane flying due east at 36.0 m/s drops a bale of hay from an altitude of h = 52.8 m, as shown below. If the bale of hay weighs F = 161 N, what is the momentum of the bale the moment before it strikes the ground? Give both magnitude and direction...
15. ### How do you find impulse?

oh okay, got it. thanks! :)
16. ### How do you find impulse?

Homework Statement Before a collision, a 26 kg object is moving at +10 m/s. Find the impulse that acted on the object if, after the collision, it moved at the following velocities. a) +8.0 m/s b) -8.0 m/s Homework Equations Impulse = change in momentum = mass * change in...
17. ### How to find angular acceleration

Homework Statement A propeller slows from 450 rev/min to 200 rev/min in 3.50 s. What is its angular acceleration? Homework Equations ac = v^2/r and v = rw The Attempt at a Solution I know this is probably a simple problem, but what do the variables in the relevant equations refer to?
18. ### Circular Acceleration & Force

fnet = m*a, so fnet = 610 * 11.58 fnet = 7063.8 ?
19. ### Circular Acceleration & Force

i think newtons are basically Kg m/s^2, if so, how do i figure that out from the information given? thanks a lot for your help
20. ### Hang time, range, maximum height

the 60 degrees? would it be put in the calculator as sin(60^2) or sin(60)^2, does it make a difference?
21. ### Hang time, range, maximum height

Homework Statement Find the ball's hang time, range, and maximum height. A player kicks a football from ground level with an initial velocity of 27.0 m/s, 60.0° above the horizontal. Find the ball's hang time, range, and maximum height. Assume air resistance is negligible. Homework...
22. ### Circular Acceleration & Force

Homework Statement A 610-kg racing car completes one lap in 14.3 s around a circular track with a radius of 60.0 m. The car moves at constant speed. (a) What is the acceleration of the car? (b) What force (newtons) must the track exert on the tires to produce this acceleration...
23. ### Kinematics of a thrown football - Find the path

^ that was right, thank you so much!
24. ### Kinematics of a thrown football - Find the path

- A quarterback throws a football at 25 m/s at a certain angle above the horizontal. If it took the ball 3.2 s to reach the top of its path, how long was it in the air? - I have absolutely no idea how to do this :(