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Newton's Second Law

The acceleration of an object as produced by a net force is directly proportional to the magnitude of the net force in the same direction as the net force, and inversely proportional to the mass of the object.

F = ma

Where force is measured in Newton’s

Newton’s second law of motion pertains to the behavior of objects for which all existing forces are not balanced. The second law states that the acceleration of an object is dependent upon two variables, the net force acting upon the object and the mass of the object.

For example, a car, which weighs 900 kg is out of gas. The driver is trying to push the car to a gas station and makes the car go 0.06 m.s^2. What is the force the driver is applying on the car?

F = 900kg * 0.05m/s^2

F = 45 N

Newton's laws of motion and friction

The floor of a railroad flatcar is loaded with loose crates having a coefficient of static friction of 0.48 with the floor. If the train is initially moving at a speed of 52 km/h, in how short a distance can the train be stopped at constant acceleration without causing the crates to slide over the floor?

Motion with variable mass

A spherical raindrop of radius a, falls from rest under gravity. It falls through a stationary cloud so that, because of condensation, its radius increases with time at a constant rate k. Find the distance fallen by the raindrop after time t.

Newton's Second and Third Law of Motion

1. Consider a plane that flies due east on a trip, and then returns due west following the same exact route. Imagine also that there are no winds in each trip. Flying due east, the plane flies with the rotation of the Earth, while flying due west, it flies against the rotation. Will the flight times be the same? Different? Why?

Problem based on Newton's Second Law of motion

If a body is subjected to several forces, we must first find the net force on the body and then apply F=ma to determine its acceleration. For instance: A pail of water of mass 20 kg is being lifted by a rope from a well. It is ascending with an acceleration of 2 m/s^2. Determine tension in the rope.

Two forces on a particle

1.) A particle experiences two forces. One constant force is given as F = F_0 x(^) (vector F = F(initial) * x(unit vector)) and the other force is a drag force that is proportional to the velocity with proportionality constant ß. Write out Newton?s 2nd Law for this particle and solve the differential equation for the parti

Applications of Newton's Laws: Horizontal force applied

See attached file. What horizontal force must be applied to the cart shown in the figure in order that the blocks remain stationary relative to the cart? Assume all surfaces, wheels, and pulley are frictionless. (Hint: Note that the tension in the string accelerates m1.)

Newton's Laws of Motion: Slipping vs. Tipping

Please also see the attached file. The fig. shows a uniformly dense rectangular brick of length a, height b resting on a rough inclined plane of angle theta. The interface between surface and brick has associated coefficients of friction us, uk. A force F is applied as indicated. a) For F = 0, and varying theta, obtain an

Newton's Second Law: Mass Questions

See attached file. Please provide a stepwise solution. Mass A (25kg) is fixed to a spring of spring constant k=500N/m and slides on a frictionless surface. A second mass, Mass B (10kg), sits above Mass A. The coefficient of static friction between the surfaces of A and B is µs=0.7.

Impulse and force exerted by a bat

1. A 0.2 kg baseball is traveling at 40 m/s. After being hit by a bat, the ball rebounds with a velocity of 509 m/s. Find a) the impulse and b) the average force exerted by the bat if the ball and bat are in contact for 0.002 s. 2. A 0.11 kg tin can is resting on top of a 1.7 m high fencepost. A 2.0 g bullet is fired hori

Finding the Acceleration of a Mass on a Frictionless Pulley

A 2.0 kg mass and a 5.0 kg mass are attached to a lightweight cord that passes over a frictionless pulley. The hanging masses are free to move. Choose coordinate systems for the two masses with the positive direction up for the smaller mass and down for larger mass. (a) Create a pictorial model. (b) Create a physical model w

Normal force of chair

A chair of mass 13.0 kg is sitting on the horizontal floor; the floor is not frictionless. You push on the chair with a force = 38.0 N that is directed at an angle of 43.0 degrees below the horizontal and the chair slides along the floor. Use Newton's laws to calculate the normal force that the floor exerts on the chair.

Free-Body Diagram: Determining Tension and Reaction

A 12 lb bowling ball is suspended by a cord and leaning against a frictionless wall as shown (see diagram). The diameter of the ball is 30 cm and the line segment of AB is 60 cm. a) Make a free-body diagram b) Determine the tension T in the cable c) Determine the reaction at point B if: i) the system is at rest ii

Physics: Friction Force Across Various Surfaces

In order to slide a heavy desk across the floor at constant speed, you have to exert a horizontal force of 500 newtons. Compare the 500-newton horizontal pushing force to the frictional force between the desk and the ground. Is the frictional force greater than, less than, or equal to 500 newtons? Explain.

Find rocket thrust, inteval between ignition and lift-off

Please provide a detailed solution to the following problem: A rocket stands vertically on a launching pad, the mass of the fuel and the rocket is 1.9*10^3 kg. On ignition, gas is ejected from the rocket at a speed of 2.5*10^3 m/s relative to the rocket, and fuel is consumed at a constant rate of 7.4 kg/s. Find the thrust of

Force and energy

It is not uncommon during the service of a professional tennis player for the racket to exert an average force of 156.0 N on the ball. If the ball has a mass of 0.070 kg and is in contact with the strings of the racket for 0.030 s, what is the kinetic energy of the ball as it leaves the racket? Assume that the ball starts from r

Physics: Bone Stress and Ball Path

See the attached file. 1. Someone shoots a gun while holding their arm stiffly outstretched in front of them and with the back of their shoulder braced against a wall. The bullet leaving the gun has a mass of 2.5 g and is traveling at 380 m/s (.22 caliber). It reaches this velocity (from rest) in 0.0001 s. Assuming that al

Physics: Speed of a Rocket

A model rocket is constructed with a motor that can provide a total impulse of 29.0 N *s. The mass of the rocket is 0.175 kg. What is the speed that the rocket achieves when launched from rest? Neglect the effects of gravity and air resistance.

Calculate Thrusting Force of Car Driving Uphill

A car goes up some hill at an angle theta. The FBD shows that in the y-direction: n = mg*cos(theta), where n is the normal force. In the x-direction: T - mg*cos(theta) - mu*(mg*sin(theta)) = m*a_x (where T is the thrusting force of the car). Is it possible to figure out what the thrusting force will be before-hand,

Motion of blocks due to tensions in the ropes

3 blocks are pulled at a constant speed. what is the tension in the other ropes? the 3 blocks have a mass of M1= 3kg M2 = 2 kg M3 = 7 kg tension in rope between block 1 and 2 is unknown T1 tension in rope between block 2 and 3 is 10N (T2) tension in rope in front of block 3 is unknown (T3) Hint: there are other forces a

Newton's Law is highlighted.

A 2.0 kg box rests on a plank that is inclined at an angle of 65° above the horizontal. The upper end of the box is attached to a spring with a force constant of 16 N/m, as shown in Figure 6-38. If the coefficient of static friction between the box and the plank is 0.29, what is the maximum amount the spring can be stretched an

Newtons' second law is applied.

You step into an elevator at the 10th floor and press the 2nd-floor button. The elevator accelerates downward briefly as it picks up speed. There are two forces acting on you: the floor pushing up on you and gravity pulling down. Compare these two forces while the elevator is accelerating downward. explain your answer in terms

Newton's Laws of Motion: Bio-Mechanics

Need help with the equation/solution to this problem. An individual weighing 600 N stands still with her hips flexed. Her hip extensor muscles are contracting with a force of 3000 N, and her ankle plantarflexor muscles with a force of 3200 N. What is the magnitude of the ground reaction force acting on her?

Newton's second law and friction: Example problem

Q. Calculate the minimum applied force required to drag the crate at constant speed up an incline of 25 deg. assuming the coefficient of friction does not change. Mass of crate = 50 kg Coefficient = 0.425

Coefficients of Friction and Maximum Acceleration

A 100 kg box of dimensions 50 cm x 50 cm x 50 cm is in the back of a flatbed truck. The coefficients of friction between the box and the bed of the truck are Us= 0.40 and Uk= 0.20. What is the maximum acceleration the truck can have without the box slipping?

Laws of Motion: Variable Force

A table of height 1 meter has a hole in the middle of its surface. A thin, gold chain necklace, of length 1 meter, is placed loosely coiled close to the hole. One end of the chain is pulled a little way through the hole and then released. Friction is negligible, and, as a result, the chain runs smoothly through the hole with inc

Determining Speed Variations: Gun Example

A gun is fired straight up. Assuming that the air drag on the bullet varies quadratically with speed, show that the speed varies with height according to the equations: v^2 = g/k - Be^(2kx) (downward motion) v^2 = Ae^(-2kx) - g/k (upward motion)

block and pulley system

In the system (shown in the attachment), the block of mass M1, is on a rough horizontal table. The string that attaches it to the block of mass M2 passes over a frictionless pulley of negligible mass. The coefficient of kinetic friction µ _k between M1 and the table is less than the coefficient of static friction µ_s. a.) D

Newton's Laws of Motion: Friction

1. A father pulls his young daughter on a sled with constant velocity on a level surface through a distance of 25 m. The total mass of the sled and the girl is 45 kg and the coefficient of kinetic friction between the sled runners and the snow is .35 The force exerted by the man is applied at an angle of 30 degrees with resp

Tension and Force that the Axle Exerts on the Pulley

A 12.0 kg box resting on a horizontal, friction-less surface is attached to a 5.00 kg weight by a thin, light wire that passes over a friction-less pulley. The pulley has the shape of a uniform solid disk of mass 1.50 kg and diameter 0.600 m (see attachment). a) After the system is released, find the horizontal tension in the