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Browsing Animations: Forces
14 Animations
bppb6.iwp
The animation shows a spherical object falling through a fluid with acceleration a = (k/m)v-g. The positive direction is up. The object has an intial position of 0 and is released from rest. The given inputs are for an iron ball of half a milimeter radius falling in glycerol at a temperature of 22 Degrees C. The distance from the initial position of the ball to the bottom of the cylinder is 0.50 m.
fallcompare-simulation.iwp
The green ball falls in a vacuum, while the red ball experiences a drag force from the fluid in which it falls. The acceleration of the red ball is a = -g + kv**2, where g = 9.8 N/kg, v is the speed of the ball, and k is a coefficient (which we term the drag factor) that depends on characteristics of the ball and the fluid. You may change the value of k to see how that influences the red ball. The vertical separation of the two balls is displayed in the list of outputs.
fallcompare-template.iwp
Simulation of two objects falling from rest in a gravitational field. They experience air drag proportional to the square of the speed. The vertical acceleration is given by: a = -g+kv^2, where k is termed the drag factor. The objects may be assigned different drag factors. The green ball is A; the red ball B. The vertical separation of the balls at any time is provided as one of the outputs.
hookeslaw03.iwp
A platform (black) is suspended from a fixed support by a rubber band. Weight can be added to the platform. When the red stick is pulled away, the platform with its weight will oscillate vertically and eventually come to rest at its equilibrium position. The goal of the problem is to take data to find the spring constant of the rubber band and to find the mass of the platform. For the latter, you'll need one measurement other than those described below. With platform held in place by the stick, the rubber band is unstretched. Click the play buttom to pull the stick away quickly and let the platform fall. After the platform reaches its resting position, read the position to the nearest 0.001 m. (In order to make the motion damp more quickly, increase the value of the damping coefficient.) Add 0.1 kg of mass to the plaform and click Reset. Then play the animation to see the new equilibrium position. Record the reading. Continue to add mass in increments of 0.1 kg and measure the equilibrium position each time. Tic marks are placed every 0.05 m to aid in taking readings.
incplane-template.iwp
An object slides down an inclined plane. The angle of inclination of the plane and the coefficient of kinetic friction may be adjusted.
incplane04.iwp
An object slides down an inclined plane under the influence of gravity and kinetic friction. The plane makes an angle of 30 degrees with the horizontal.
incplane05.iwp
An object slides down an inclined plane. The coefficient of kinetic friction, which is initially 0, can be changed. The inclination of the plane, the initial x-coordinate of the block, and the initial velocity can also be changed. Vectors in black represent the fores acting on the plane. The vector in red is the net force. The scale factor may be changed to increase or decrease the size of all the vectors by the same factor.
leaf.iwp
The physical situation for this problem is like that of the falling leaf where the leaf experiences a lift force that is proportional to and perpendicular to its velocity. In this case, we treat the leaf as if it were a particle, even though we know that its shape is essential to the drag force that it experiences. Unlike the falling leaf problem, we include the option of a non-zero initial velocity. Both the magnitude and direction of this velocity can be entered. The acceleration of the particle at any time is given by: a = -jg + j(k/m)v, where a and v are understood to be vectors in the complex plane (phasors). It is intended that you use your knowledge of the equations x(t) and y(t) for this motion in order to do the following problems. While the equations that you derived for homework assume Vo=0, your knowledge of the forces involved should help in doing the problems. For each path, record the inputs that you use: lift coefficient (k), mass (m), g-field (g), initial speed (Vo), initial angle (theta). Explain, with reference to the equations of motion and/or the forces why those inputs work. Use force diagrams to improve your explanations. Example problem: Make the object move in a straight vertical line. Solution: This will occur if gravity is the only force acting and the initial velocity is zero. Change the lift coefficient and the initial speed to 0. Play the animation. Make the object move in the following paths: 1. parabolic 2. complete circle at constant speed 3. constant speed along the x-axis (with non-zero lift and g) 4. cycloid totally in quadrant IV 5. cycloid totally in quadrant I 6. looping (but not circular) 7. any path with portions in both quadrants I and IV One more problem: Describe another physical situation in which the mathematics is identical to the previous situation but for which the forces are different in nature. Make it clear why the mathematics is identical to that of the previous situation.
mass-bppb-3.iwp
The animation allows you to check your calculated results against your measured results for a sphere falling through a fluid. Begin by entering your measurements in Input boxes. For the mass of the ball, enter the value that you calculated. The motion of the red ball uses the theoretical equation for position as a function of time. This assumes laminar flow and uses the mass that you calculated. The motion of the blue ball is the same as what you measured directly using distance and time of fall. Under Outputs, the Separation is the vertical distance between the blue and red balls. If you calculated mass correctly, the Separation should always be 0 or very nearly so.
projectile-drag-2.iwp
The green projectile is subject to a v-squared drag force. The red projectile is subject to a v drag force.
projectile-drag-lift-2.iwp
The projectile is subject to a downward gravitational field, a drag force opposing the velocity and proportional to v-squared, and a lift force proportional to and perpendicular to the velocity.
stopblock01.iwp
An object moving horizontally is slowed by a force of kinetic friction. Adjust the initial velocity so that the right side of the block stops at the right-hand edge of the screen.
turntable04.iwp
A turntable accelerates uniformly. Three discs are held in place by static friction. In what order will the discs break free?
turntable05.iwp
A penny on a turntable slides off when the turntable reaches a certain frequency. What is the coefficient of static friction of the turntable? How does the result depend on the radius of the path?