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Hi. I need some help with a conceptual question. "A uniform 1-meter stick that is supported by a fulcrum at the 25-cm mark is in equilibrium when a 1-kg rock is suspended at the 0 cm end. Is the mass of the meter stick greater than, equal to, or less than the mass of the rock?" I thought the answer would be that the mass o

Buoyant force on an object submerged in a liquid in equilibrium.

See attached file. To hold up a certain stationary iron anchor in air takes 200 newtons more than when it is submerged in fresh water. The density of iron is Di=7870 kg/m^3, and by definition, the density of fresh water is Dw=1000 kg/m^3. Find the weight W, of the anchor in air.

Torques in equilibrium on a leaning ladder.

A uniform bar of length L= 8 m, whose weight is 420 nt is placed into a totally frictionless, open top box in the shape of a cube whose sides are length s= 4m. Its bottom end is at a lower corner and it extends over the opposite top edge. See ATTACHMENT for a diagram with dimensions. Find P, the force the top edge exerts again

Torques on a boom in equilibrium.

A uniform boom is at an angle of 45 degrees from the ground. It is held in place by a frictionless pin at ground level. Weight A= 2230 nt is suspended from its upper end and the boom's weight B= 441 nt. A cable from its upper end to ground level makes angle 30 degrees with the ground. See ATTACHMENT for a diagram. Find T, the t

A door in equilibrium requiring application of net torque equal to zero.

A uniform, rectangular door 2.2 m high and 2.4 m wide having a weight of 260 nt is supported by two hinges. One hinge is .30 m from the top corner and the other is .30 m from the bottom corner. Each hinge supports half the total weight of the door. See door ATTACHMENT for a diagram. Find the magnitude of the total force exert


A pan of water is heated from 23 C to 78 C. What is the change in its temperature on the kelvin and fahrenheit scales? A 0.225 kg sample of tin initially at 97.5 C is dropped into 0.115 kg of water initially at 10.0 C. If the specific heat capacity of tin is 230 J/kg *C (its a dot before "C" but im not exactly sure how t

Spring supporting two blocks without friction

A 0.7 lb block rests on top of a 0.5 lb block supported by but not attached to a spring of constant 9 lb/ft. The upper block is sudenly removed. A) Determine the maximum velocity reached by the 0.5 lb mass B) the maximum height reached by the 0.5 lb mass Please see attachment

Rotational equilibrium

I am trying to help my brother (in high school) understand how to solve rotational equilibrium problems. What he needs is an explanation on how to approach these problems. I understand each problem is different, but I imagine there must be a general method for solving them. I have put a problem below so that hopefully you could

Rigid Objects in Equilibrium, Center of Gravity

A lunch tray is being held in one hand. The mass of the tray itself is 0.200 kg, and its center of gravity is located at its geometrical center. On the tray is a 1.00-kg plate of food and a 0.250-kg cup of coffee. Obtain the force T exerted by the thumb and the force F exerted by the four fingers, Both forces act perpendicular t

Tension - Equilibrium and Elasticity: Five problems

The graphs are attached in word document. 1. The system in the picture is in equilibruim with the string in the center exactly horizontal. Find (a) tension T 1 , (b) tension T 2 (c) tension T 3 (d) angel pheta 2. The system in the picture is in equilibrium. A concrete block of mass 225 kg hanfs from the end of the unif

Fluid Mechanics: bouyance, harmonic motion, period

Consider an object with height h, mass M, and uniform cross sectional area A floating upright in a liquid with density p. a.) Calculate the vertical distance from the surface of the liquid to the bottom of the floating object at equilibrium. b.) A downward force of magnitude F is applied to the top of the object. At the

Speed of object in revolutions around a circle: puck of mass tied to a string

A puck of mass 0.270 kg is tied to a string and allowed to revolve in a circle of radius 1.09 m on a frictionless horizontal table. The other end of the string passes through a hole in the center of the table, and a mass of 1.24 kg is tied to it (see figure in attached Word file). The suspended mass remains in equilibrium while

Calculate tension in a steel wire under water connecting a buoy to the sea bed

A spherical buoy is tied to the sea bed by a steel wire so that exactly half the buoy is above the water surface. If the diameter of the buoy is 1.3m and the mass of the buoy is 20kg: a) determine the tension in the wire b) if this tension produces an extension in the steel wire of 4.0mm, calculate the length of the wire.

Calculate the equilibrium temperature of aluminum and water.

A 10kg aluminum block of (c=920J/KgC) at 75 degrees C is dropped into 100kg of water ( c=4186J/kgC) at 50 degrees C. Assuming the heat only passes between the water and the aluminum (no losses) what will the equilibrium temperature (in degrees C) be?

Uniform plank rests against a frictionless roller: coefficient

A uniform plank with a length L of 6.10 m and a weight of 445 N, rests on the ground and against a frictionless roller at the top of the wall of height h = 3.05 m. The plank remains in equilibrium for any value of theta greater than or equal to 70 degress but slips if theta is less than 70 degrees. Find the coefficient of stat

Coefficient of friction

Here is the asking problem: A cord is attached to and partially wound around a cylinder of weight W and radius r which rests on an incline as shown. Knowing that the coefficient of static friction between the cylinder and the incline is 0.30, find the smallest allowable value of angle if the cylinder is to remain in equilibri

Working with static equilibrium and tension.

A scaffold of mass 35 kg and length 5.8 m is supported in a horizontal position by one vertical cable at each end. A window washer of mass 86 kg stands at a distance d from the midpoint of the scaffold. The tension in the cable nearest the worker is twice the tension in the other. a) What is the tension in the cable nearest th

Static Equilibrium

The system in figure 13-45 is in equilibrium. A mass of 225 kg hangs from the end of the uniform strut. The tension T in the supporting cable is measured to be 6,910 N. a) What is the mass of the strut? b) What is the vertical component of the force exerted on the strut by the hinge? c) What is the horizontal component of th

Calculating the period of oscillation of a mass/spring system.

If a mass of 600.0 g is hung from the bottom of a vertical spring, the spring will stretch 28.0 cm. Now the hanging mass is removed, and the spring is placed horizontally on a frictionless table. One end of the spring is held fixed and the other end is attached to a 370.0 g mass. The mass is then pulled out a distance of 14.0 cm

Equilibrium with torques on a cylinder on an inclined plane

A unifom cylinder, mass M= 15 kg, rests on a plane inclined at angle b=30°, held stationary by a cord attached to the plane at angle a= 50° which applies tangential force C to the cylinder. A mass m= 5 kg is suspended on a cable which is wrapped on the surface of the cyiinder. The radius R is unknown. See the attachment for a