# Search results

1. ### X-ray production and ionization energy

I am confused with the Kvp and Kep. I know that In the x-ray tube, after heating the filament and the electron cloud if formed, then the step-up transformer is going to increase the voltage and reduce the current to produce a high potential difference to that electrons will accelerate from the...
2. ### Amplitude relation with periodic time

Homework Statement Ql: Which sound wave will have its crests farther apart from each other - a wave with frequency 100 Hz or a wave with frequency 500 Hz? Homework Equations Frequency= 1/ periodic time The Attempt at a Solution I did it like that: I just found the periodic time for each...
3. ### Ideal Gas Law and pressure

Homework Statement An ideal gas has a molar mass of 40 g and a density of 1.2 kg m-3 at 80°C. What is its pressure at that temperature? Homework Equations PV=nRT R constant= 8.314 n= number of moles T= tempreture in kelvin density=Mass/ Volume The Attempt at a Solution i simply solved it like...
4. ### Rotational moment of inertia for 3 balls on a pipe

Homework Statement Homework Equations The Attempt at a Solution i just dont know from where to take the R which is colored with brown, in the 2(MR^2), what is the R here exactly, because i took the radius of the sphere , but i get different answer althought it's near.
5. ### Will it rotate?

Homework Statement Homework Equations torque= F*r*sintheta total force on y= 0 The Attempt at a Solution how come it will rotate in this situation?? espicially that he is ignoring the weight force of the rod! i knew that i ignored the mass of the rod when he said total force on y= F -F. if...
6. ### Rotational inertia hoop around a central axis

Homework Statement Homework Equations I= mr^2 for a hoop around a central axis I= 1/12 (m)(l)^2 for thin rod about axis through center perpendicular to lenght The Attempt at a Solution I am totally confused. i said first that the three masses each will make a hoop shape so i found I=mr^2...
7. ### B When a particle is rotating about an axis "r" away, is its linear velocity constant?

If talking about a particle rotating around an axis away from it by r. if the particle is moving with constant angular velocity ω. is the linear velocity constant or no? Now what I know is that since we have Vt= ωr, so r doesn't change, as well as ω, so Vt is said to be constant. but I think...
8. ### Static equilibrium: Find the tension in a support cable

Homework Statement Homework Equations Σtorque = 0 Σfx=0 Σfy=0 torque= F r sinθ (θ is the angle between the r and the F) The Attempt at a Solution OKay, now i know how to solve this, but it's like i asked myself, how to know if this is a question that i am supposed to use Σfx=0 and Σfy=0...
9. ### Incline with friction and two blocks

Homework Statement The coefficient of kinetic friction between the block of mass m1 = 2.5 kg and the plane in Fig. 6 below is 1/6. Find (a) the acceleration of the block and (b) the tension in the string. Take g = 10 m/s2. Homework Equations Fnet=ma The Attempt at a Solution please i don't...
10. ### Tension on a massive rope

Homework Statement A system, consisting of a wide rope of mass 0.10 kg between two blocks each of mass 0.10 kg, is lifted by an applied force F = 9.0 N (Fig. 4 below). (a) Find the acceleration of the system. Find the tension at (b) the top of the rope, and (c) the bottom of one-fifth of the...
11. ### B Tension of a massive rope

[moderator: text edited to change the phrasing.] There is a question that that says: a 50 kg weight is suspended from the bottom part from a rope. If the rope has a weight of 100N. Then what is the tension at each end of the rope( the top part connected to the ceiling and the bottom part to...
12. ### Force applied on the pulley of a system

Homework Statement two blocks of masses 8kg and 4kg respectively are connected by a string as shown in firgure. calculate their accelerations if they are initially at rest on the floor. after a force of 100N is applied on the pulley in the upward direction (g=10 m/s). Homework Equations Σf=ma...
13. ### Tension and equilibrium

Homework Statement you want to hang a 15-N picture as in part (a) using some very fine twine that will break with more than 12 N of tension can you do this? what if you have it as illustrated in part (b) of the figure? Homework Equations Σf=ma The Attempt at a Solution [/B] okay i started...
14. ### Will this system move?

Homework Statement two blocks of mass m sit on a frictionless surface and are connected by a massless, unstrechable string that rolls on a massless, frictionless pulley as shown. the second mass sits on an inclined tipped at an angle θ relative to horizontal. at time t=0, both masses are...
15. ### B Kinetic friction direction on two stacked blocks

If i have two blocks on top of each other and there is friction between the two blocks and it's a kinetic friction ( given μk). if i was given the force applied on the lower block to the right direction for example. ignoring the friction between the lower block and the ground, i tried to draw...
16. ### Two blocks, a fixed pulley and friction

Homework Statement a mass m1 is attached to a second mass m2 by an acme (massless, unstretchable) string. m1 sits on a table with which it has coefficients of static and dynamic friction μs and μk respectively. m2 is hanging over the ends of a table, suspended by the taut string from an acme...
17. ### Friction, mass and tension

Homework Statement In the figure above a block of mass m is connected to a block of mass M > m by a string. Both blocks sit on a smooth surface with a coefficient of kinetic friction µk between either block and the surface. In figure a), a force of magnitude F (large enough to cause both blocks...