What is Newton's second law: Definition and 264 Discussions
In classical mechanics, Newton's laws of motion are three laws that describe the relationship between the motion of an object and the forces acting on it. The first law states that an object either remains at rest or continues to move at a constant velocity, unless it is acted upon by an external force. The second law states that the rate of change of momentum of an object is directly proportional to the force applied, or, for an object with constant mass, that the net force on an object is equal to the mass of that object multiplied by the acceleration. The third law states that when one object exerts a force on a second object, that second object exerts a force that is equal in magnitude and opposite in direction on the first object.
The three laws of motion were first compiled by Isaac Newton in his Philosophiæ Naturalis Principia Mathematica (Mathematical Principles of Natural Philosophy), first published in 1687. Newton used them to explain and investigate the motion of many physical objects and systems, which laid the foundation for Newtonian mechanics.
I have absolutely no idea how to do this problem and I need help with steps, formulas/equations, etc. So, here it goes!
David Purley, a racing driver, survived deceleration from 173 km/h to 0 km/h over a distance of 0.660 m when his car crashed. Assume that Purley's mass is 70 kg. What is the...
Only two horizontal forces act on a 3.0 kg body. One force is 9.0N, acting due east, and the othr is 8N, acting 62 degrees north of west. What is the magnitude of the body's acceleration?
Fnet= ma ...so I took that to mean F1x + F2x = ma
F1x = 9 cos 0 = 9
f2x = 8 cos 62 = 3.76
a = (9 +...
Is someone able to proove the invariance under Galilean transformations of F=dp/dt within a system of variable mass? In particular is the momentum invariant? i.e. p=p', as Goldstein states? Please answer me! :wink:
Three astronauts, propelled by jetpacks, push a 120kg asteroid toward a processing dock, exerting the forces
F1 = 32N at 30 degrees above the horizontal
F2 = 55N on the horizontal
F3 = 41N below 60 degrees below the horizontal
what is the asteroids acceleration in unit vector notation...
This question is driving me insane...
An arrow, starting from rest, leaves the bow with a speed of 25.0 m/s. If the average force exerted on the arrow by the bow were doubled, all else remaining the same, with what speed would the arrow leave the bow?
Of course, instinct says 50 m/s, but...
Hi I got a few questions that I could not answer about Newton's Second Law of Motion. Can someone please help me?
1) A 1.08 x 10^3 kg car uniformly accelerates for 12.0s from rest.. During this time the car travels 132 m north. What is the net force acting on the car during this acceleration...
Hi.
I have this problem:
The fastest cars can travel at 350km/h. When you take the foot of the gaspedal the air will decrease the speed of the car. This leads to a retardation (I hope it's the right word for it) at 1.1 g. Which force (N) will affect the driver (80kg)? The weight of the car...
A block of mass 2.0kg is placed on a smooth plane, inclined to the horizontal at an angle of 15degrees. The force of gravity, acting straight down on the block, is 20N.
a) What is the acceleration of the block down the plane?
I'm having trouble with this because I know:
Net...
Science howework
A crate rests on a horiontal floor. Only gravity and the support force of the floor act on it. A slight pull P is exerted on the crate, not enough to move it. A force of friction f now acts on it.
is f, less than, equal, or greater than P?
is the net force on the crate...
The differential equations that are mostly used in physics are second order, so I am wondering about the third order (or more)? It is clear that in real life, like when driving a car, acceleration changes many times and continuously, but do people ever add d3x/dt3 to Newton's second law? Is it...
I was reading a section about rocket propulsion in my general physics text and it came up with the following formula:
m \frac{dv}{dt} = - v_{ex} \frac{dm}{dt}
I don't have much trouble with this formula, but then it went ahead and substituted m dv/dt as the thrust experianced by the...
A string wrapped around a cylinder, and is held by a hand (to the up right of the cylinder so the cylinder is rotating clockwise) that is accelerated upward so that the centre of mass of the cylinder does not move. a) Find the tension in the string. b) Find the angular acceleration of the...
Hello everyone.
I'm having a little trouble understanding the whole "ball and bowl" problem using Newton's Second Law. What I'm talking about involves a small shpere of mass m and radius r, rolling down a "bowl" (more like a hemisphere of radius R). How would one go about finding the KE of...
This question has been troubling me... :
A physics teacher decides to use bathroom scales (calibrated in Newtons) in an elevator. The scales provide a measure of the force with which they push up on the teacher. When the lift is stationary the reading on the bathroom scales is 823 N. What...