155 Answered Questions for the topic Forces
Very hard hanging rod problem
A straight rod of 30 cm and 600 g mass is horizontally hanged on two upright, parallel and light threads, both of them attached with distances of 5 cm and 10 cm from its ends. Find tension forces... more
A 10.0 kg crate initially at rest sitting on a floor with a coefficient of static friction of 0.20 is pushed with a force of 15 N for 4.0 s. What is the work done?
15 J 60 J 10 J 600 J 0
Force Applied and Impulse/ Newton's Third Law
How does the applied force of an object determine impulse?How is impulse and Newton's Third Law relate to changes in momentum for colliding objects?
Protons experience both electric and gravitational forces. Comparing the forces between 2 protons in a nucleus, it is correct to state that
A electric force is much stronger than the gravitational forceB gravitational force is much stronger that the electric forceC electric force is shorter range than the gravitational forceD... more
The 100m dash can be run by the best sprinters in 10.0 s.
A 65 kg sprinter accelerates uniformly for the first 50m to reach top speed, which he maintains for the remaining 50 meters.a) What is the average horizontal component of force exerted on his feet... more
Physics- Forces/Free Body Diagram Questions
A horizontal force of 76N is required to slide a 23kg box across a tile floor at constant velocity. What is the coefficient of sliding friction between the box and the floor? PLEASE I AM STRUGGLING!
A 0.75 kg ball of clay is thrown at the wall at a speed of 12 m/s (which after it sticks). It takes 0.1 seconds for the ball to come to a complete stop. What is the deceleration of the ball?
What role does static friction force play for a rolling object? How can I know what direction it points?
Fundamentally, what does a friction force do for a rolling object? I am very confused by the way my textbook explains it. In my textbook , it says: A wheel rolling on a horizontal flat surface at... more
Why shouldn't gravity be a force?
Why shouldn't gravity be a force? I am interested to know the reasons why we shouldn't treat gravity as a force in, for example, General Relativity. Won't we be able to model it accurately by... more
Why is less force required to open a door when we apply a force at a greater distance from the hinge?
I know that the magnitude of a torque increases with the distance from the axis of rotation. What is the reason of that : how can a force exert a greater torque when the force is applied at a... more
What's the core difference between the electric and magnetic forces?
I require only a simple answer. One sentence is enough... (It's for high school physics)
What physical forces pull/press water upwards in vegetation?
Each spring enormous amounts of water rise up in trees and other vegetation. What causes this stream upwards? Edit: I was under the impression that capillary action is a key factor: the original... more
I'm trying to understand tension. So here it goes: I'll start from the beginning. Let's assume I'm in space and can move around and apply forces. Let's say a rope is attached to a body(which is... more
Small car colliding with large truck?
A small car collides with a large truck. Why do both vehicles experience the same magnitude of force? Wouldn't the large vehicle experience less force than the small one?
When displacement isn't possible?
Stop me if i'm wrong but displacement is, for example, when you enter a bathtub the water level rises around you. What happens when displacement isnt possible? I'll give an example. I have two... more
Why can't charged objects exert electrostatic forces on heavier objects?
We know that, for example, amber rubbed with fur attracts bits and pieces of straw, paper, Styrofoam, etc. which are all light objects. Why don't they attract heavier objects, likewise?
When a ball is tossed straight up, does it experience momentary equilibrium at top of its path?
This question has been asked many times all over the Internet and answers can be found on places such as yahoo and ask.com, but I'm not satisfied with those answers and I don't trust the validity... more
Why do we take small steps while walking on ice?
> When we walk on ice we should take small steps. Small steps ensure: > > a.)larger friction. > > b.)small friction. > > c.)larger normal force. > > d.)smaller... more
Which is easier, pushing or pulling?
It is generally assumed, from a person's perspective, that pushing a cart is more easier than pulling one. But why? Is there any difference in terms of force required to achieve the same amount of... more
Why don't we consider jerk in physics classes?
When I got more into physics, I started asking myself if just like acceleration represents the growth of speed, something else could also represent the growth of acceleration itself. And it came... more
What is force? How does a constant force output a nonconstant power?
For a constant force, P=Fv. I understand the mathematical derivation of this, but this seems to me, intuitively, to be nonsense. I feel that my discomfort with this comes from a fundamental... more
Why is a book on a table not an example of Newton's third law?
My textbook explains Newton's Third Law like this: > If an object A exterts a force on object B, then object B exerts an equal but opposite force on object A It then says: > Newton's 3rd... more
Why does Newton's third law exist even in non-inertial reference frames?
While reviewing Newton's laws of motion I came across the statement which says Newton's laws exist only in inertial reference frames except the third one. Why is it like that?
Why does an unhinged body rotate about its centre of mass?
If a force is applied to a body which does not act through its centre of mass, it rotates about its centre of mass and not any other point. Why?
What atomic forces are acting to resist me pushing an air filled bottle underwater?
Yes air is less dense than water but how does the bottle know to rise or indeed to move? It's not electromagnetism I think. Does this have a relation to gravitational forces? Is it to do with the... more