Force applied Definition and 171 Threads

Homework Statement A sling shot can launch a 50gram rock at a speed of 24m/s if it is stretched .4meters before release. Find the average force applied to the rock Homework Equations Spring force = 1/2*k*x^2 1/2kx^2 = 1/2mv^2 The Attempt at a Solution tried to solve for K...

When a force is applied to a pendulum, the pendulum sways back and forth until it eventually stops. In this problem however, a force is applied at uneven time intervals while the pendulum is still in motion. The force is always applied in the same direction. A data set is given containing...

Hello, First post, go easy. Trying to do some basic calculations on how to find when a steel cantilever beam will yield when a load is applied to the free end of the beam. I have attached my best MS Paint diagram of the problem. Assume the left end is clamped and essentially a fixed end...

Homework Statement What is the average force applied by a 75 g bullet that leaves a gun at 1350 m/s and hits a target 75m from the barrel of the gun? Homework Equations F = ma The Attempt at a Solution First I had the equation F = ma, and began filling in all the variables I could...

Homework Statement An object of mass is placed at rest at the point x=0 on a horizontal table and at time t=0, a horizontal force is applied to it given by Fx = c1t where c1 is a known positive constant. The coefficient of friction between the table and the object is u. If friction force...

Homework Statement Two forces of equal magnitude are applied simultaneously on the ends of a bar of length L. In another reference frame, moving with velocity v relative to the bar (with v being parallel to the length L), the forces are not applied at the same time, generating momentum. I...

Homework Statement A box of books weighing 319 N is shoved across the floor by a force of 485 N exerted downward at an angle of 35^degrees below the horizontal. a) If uk between the box and the floor is 0.57, how long does it take to move the box 4.00 m, starting from rest. b) If uk...

I have a heavy bag and I was wondering if I could find out how much force is applied when I kick it. Here's a picture describing of the problem: If some amount of force is applied that causes the bag to move x meters (first swing) in the direction of the force, how much was applied? The...

There is a box of mass m on a wedge of mass M with angle θ (the triangle also has a angle of 90 degrees). I need to find the force applied on the little mass, this is what I got: F=-mgsinθ+Mgsinθ Where the first term refers to the force of gravity applied to the mass m and the second term...

Hello Everyone! I have a question regarding a Quantum problem I am trying to solve in L. Brown's Quantum Field Theory book, Chapter 1, Problem 4.f. Homework Statement I have a question which asks me to compute [p][/n], i.e. the probability that the ground state (n=0) is brought to the...

Homework Statement if the coefficient of friction between a 30 kg metal block and the floor is 0.16, what force is required to roll this block across the floor at a uniform speed? how much work is done? find : weight of force, normal force, force applied and fricitional forceHomework Equations...

Torque is defined as: τ = rxF this means that the farther from the rotation axis of a body a force is applied, the more it will tend to rotate the body. My question is: Can anybody give me a simple argument that a force applied farther from the rotation axis should be better at...

Homework Statement velocity changes when force applied perpendicular i can't understand a simple question. can u help me what i know is that speed in short its magnitude does not change when force is applied perpendicular.its direction only changes so does the velocity. what i don't...

I understand that if we apply a force on the axis of rotation of a spinning disc, the torque is in a different direction, and the axis is moved in a direction perpendicular to the direction in which the force upon the axis was applied, determined by the right-hand rule. But what if the force...

In a place with no friction, I have a rocket that applies a constant force f to a weight of mass m, and between them is a spring with constant k. I assume that the mass of the spring is negligible. As the three objects accelerate, by how much does the spring contract? My intuition tells me...

1. I'm in my first year of physics, and the end-of-year project is a bit of a doozy: find two examples of misapplied physics in movies and explain how it's wrong. For my first example, I chose a scene from the movie "The Iron Giant," in which the Giant picks up a car with Hogarth, our child...

Homework Statement First of all, in order to avoid any confusion, let me precise that I use Gaussian units. I.e. k=1 rather than \frac{1}{4\pi \varepsilon _0}. An infinite conductor plane is kept at a potential worth 0. A point-like charge can be found at a distance d from the plane. Using the...

Homework Statement FYI - I don't have any knowledge on the mechanical aspects of electric motors. you're given a 400 hp electric motor that needs to run at varying rpms. The armature is 1200 lbs and is 800mm long with a diameter of 500 mm. the air gap that exists is 2.5 mm. At 800 rpm the air...

Homework Statement In the figure the man hanging upside down is holding a partner who weighs 570 N. Assume that the partner moves on a circle that has a radius of 6.50 m. At a swinging speed of 4.25 m/s, what force must the man apply to his partner in the straight-down position? Homework...

Homework Statement A 0.50 kg skateboard is at rest on a rough, level floor on which two lines have been drawn 1.0 m apart. A constant horizontal force is applied to the skateboard at the beginning of the interval, and is removed at the end. The skateboard takes 8.5 s to travel the 1.0 m...

A 0.50kg skateboard is at rest on a rough, level floor on which two lines have been drawn 1.0m apart. A constant horizontal force is applied to the shateboard at the beginning of the interval, and is removed at the end. The skateboard takes 8.5s to travel the 1.0m distance, and it then coasts...

Homework Statement im having problems with this question...a body weighing 51kg is pulled on a horrizontal plane with coefficient of friction 0.3. a force of 300N is applied at angle x ... find the angle x? Homework Equations The Attempt at a Solution the only solution i hav come...

The other day, we were discussing cars going through turns and the max speed they could do without slipping. My teacher asked us if static or kinetic friction should be used. I answered static, because the wheels are rotating and thus not sliding over the road surface. He ended up saying the...

I have attached a figure with this, to help in understanding the problem. A ring whose circumference is attached to its center by infinite springs. Center is fixed. thickness of ring is h, width is b, Young's modulus E and moment of area I. Now a radial force is applied(shown in the figure...

Homework Statement A 2kg block & 3kg block (left & right, respectively) are on a horizontal frictionless surface connected by a spring with K=140 N/m. A 15N force is applied to the 3kg block towards the right. How much does the spring stretch from its equilibrium length? Homework...

Hi everyone: I have an 0.1" thick aluminum plate. I am mounting a component to the plate using four 8-32 screws. During use, this component will see a torque of about 35 Ib.in applied onto a shaft that is connected to it. How do I determine the force that is applied onto the four...

So this is the question summarized: Mass of the person is 75kg, the person is standing on his/her tiptoes. There are three forces acting on the foot which are: -Upward Normal force from toes - Calculated to be mg=735N (Fn) -Downward force from ankle onto foot (Fa) -Upward force from tibia to...

When calculating the amount of work done, using the force applied and the displacement, does the weight of the object do anything ?

Homework Statement A 0.15 kg baseball is pitched with a speed of 23 m/s. When the ball hits the catcher's glove the glove moves back by 0.044 m as it stops the ball. Assuming a constant acceleration of the ball, what was the average force applied by the catcher's glove? Homework Equations p...

2 boxes are stacked vertically, box A on top with box B below. Mass of box A is 15kg. Mass of box B is 30kg. There is friction between all surfaces; static coefficient of 0.40, and kinetic coefficient of 0.35. The blocks are stationary when the constant force F is applied to box B (bottom box)...

Homework Statement If an object is moving in a certain direction, with the net force also going in that direction, but the magnitude of the force is decreasing with time as it goes along. What is the speed of the object doing? Homework Equations The Attempt at a Solution Im...

Hi The magnetic force applied to electron spin magnetic moment is interpreted by Lorentz force qvXB ? I do not think so. If not, we easily understand why magnetic force can work. Regards.

Hi guys, I got this thought in my head. If I have a box of mass x, being pulled towards East and the angle \theta, then force applied to the box in order to move it on the surface with friction coefficient \mu has to be in such a way: My question is... wouldn't N be: Or, N...

I am redesigning a bicycle wheel quick release lever for a design project. I am trying to put together a force diagram as part of the project and I need to know the average force someones hand could apply to the tip of the lever to calculate the force exerted on the locking mechanism. Could...

Homework Statement Hey guys how are you all. Lets see, I'm not a physicist (mathematician actually) but I'm involved in this discussion (some may be aware...) and would like some physics help. (This is not an assessment, tutorial, university, school etc question.) Here's the scenario...

Homework Statement If you exert a force of 175 N at a downward angle of 35 degrees on a box with a total mass of 125kg for a distance of 15m, and the box and the floor have a uk of 0.25, what is the work done? Homework Equations F= (m)(a) Fk= (uk) (Fn) W = (F)(d) The Attempt at a...

Homework Statement A pair of masses M1, M2 is suspended vertically by a pair of spring, with spring constant k1, k2. ( see the attachment for the picture) a.A downward force F is applied to bottom mass. Find the downward displacements d1 and d 2 of the equilibrium positions of the Mass...

Hello all, I was looking to determine the force applied on a plate A by another plate B which is pushing down on plate A to hold it. what are all the information required to calculate the force and how? (see attached pic) Thanks

Homework Statement Suppose you are driving a light weight pickup truck, and it takes 15m of stopping distance to stop when you are traveling 5 m/s, using max. force from the brakes. 1. Suppose you really load up the truck, so that the mass of the loaded truck is twice that of the unloaded...

Hi, May I ask, if there is a sufficiently long rod falling vertically downwards due to gravity, and then at an instance, a horizontal force is applied at one end of the rod, will this force create a torque on the rod? If so, where is the axis of rotation? Second question, if a body, not...

At an altitude of 315 m above a lake, a hot-air balloon pilot drops a 2.50 kg sandbag. If the bag comes to a stop 4.50 m below the surface of the lake, what force was applied by the water on it? Mass:2.50kg velocity: 2.50kg*9.81m/s=61.31? I can't remember how to figure out what the time...

Homework Statement A 0.140-kg baseball traveling 45.0 m/s strikes the catcher's mitt, which, in bringing the ball to rest, recoils backward 11.0 cm. What was the average force applied by the ball on the glove? Homework Equations F=ma ? The Attempt at a Solution It is the whole...

Homework Statement A net force of 4N to the right is applied to a box of 6kg while moving it a distance of 3m to the right. (1)How much work is done on the box? (2)What if the force is applied at a 30 degree angle above horizontal? Homework Equations (1) W=Fdcos(angle) (2)...

Homework Statement There are two short questions I'm absolutely stumped by. And I can't even find a way to work backwards from the answer to understand them. Please help if you can, these two questions are driving me nuts ;__; Question 1) by applying a force you accelerate a ball upwards...

A weight of mass 12.5 Kg hangs from very light pulleys as shown in fig. What force must be applied to the rope so that the mass stays at rest. M=12.5 Kg W=mg a=g=9/8 m/s^2 M=12.5 Kg W = mg = 12.5 x 9.8 = 122.5 N I've done this much but I have no clue what to do now. Can someone please...

If i hit a gear/wheel with a certain force how do i calculate how the resultent rpm? Theres a picture attached to help with my explanation. thanks, Tom

I hope I am asking this in the right forum. Lets say you have a simple hand pump, similar to a bicycle pump, and you exert X amount of force on the handle. How do you calculate the resulting air pressure it creates out of the small valve at the end? Obviously friction between the O-ring...

Homework Statement The lever BCD is hinged at C and is attached to a control rod at B. Determine the maximum force \vec{P} which can be safely applied at D if the maximum allowable value of the reaction at C is 500 N. Here is a picture of the problem. It is number 4.20. "[URL...

Hi, I need to find an answer for the following question: What happens when you apply a tangential force instantenously to a disc laying on a frictionless surface? Does it rotate, translate or both? Here is an illustration for a better explanation...

I am trying to install a small crane to lift my disabled uncle into a boat. The crane is 41 inches high and the boom is 60 inches long. My uncle's weight is 250 pounds. What is the force that will be placed on the base of the crane. This answer will allow me to decide if I can mount the...