A good example that illustrates the law of acceleration is a car's increasing velocity. When a person pushes down the gas pedal, the car has positive acceleration. When the brakes are applied over a period of time, the vehicle accelerates in the negative direction. Another example is throwing a football. It travels in the direction of the line of action of a throw’s force at a speed that’s inversely proportional to the football’s mass and directly proportional to the force.
Know MoreAdditionally, when a person steps on a weighing scale, the number that appears on the scale is not exactly the person’s mass, which remains constant. It is his weight, and this changes under different accelerations. This is the reason why astronauts on the moon weigh differently than on earth.
When a person pulls a wagon containing a lesser weight than himself, the wagon's velocity changes, producing a positive acceleration. This acceleration is limited by the strength of the external force on the system.
An example of generating an external force to accelerate is the use of roller skates. It’s hard to get going when a person keeps the skates pointing forward with only the wheels in contact with the ground. To start moving, a sideways push on the wheels is necessary. However, wheels can’t turn sideways, so the person should push against the ground. This way, he will start to accelerate.
Learn more about Motion & MechanicsWhen the acceleration of an object is zero and the velocity is positive, the object continues to move at a steady velocity in the same direction. The object cannot be changing direction because direction change results in non-zero acceleration.
Full Answer >The law of acceleration is formally referred to as Newton's Second Law of Motion and defines the rate of acceleration as a product of the force exerted on the object and the mass of the object. The rate of acceleration increases as the net force increases. The inverse is true for mass, with the acceleration decreasing as the mass increases.
Full Answer >Newton’s second law states that the force acting on an object is directly related to the acceleration. The law is formulated as F = m x a, where F = force, a = acceleration and m = mass of the object in motion. In terms of Atwood’s machine, a force equal to the difference in the suspended weights accelerates the total mass, m1+ m2.
Full Answer >A 50 pound-mass dumbbell is pulled downward by the Earth's gravitational field at an acceleration of 32.174 feet-pound-mass per second squared, so the force to lift it is 1,608.7 pounds-force. Newton's second law of motion states that force is equal to mass multiplied by acceleration, gravitational or otherwise.
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