Tutor profile: Mark N.
Subject: Physics (Newtonian Mechanics)
A dense object is dropped from a tall building and falls freely with nearly zero wind resistance reaching a final speed before impacting the ground. As the first object is being released an identical second object is shot upwards at the final speed of the first object. The time it takes one to fall to the bottom and one to rise to the top is equal. Despite this, state why will the objects not meet at the halfway point?
The object in free fall is starting from rest and accelerating downwards at 9.8 m/s/s. Because it starts from rest, it is initially moving slowly and has moved only a short distance in the first few moments. The second object is shot upwards at the maximum velocity, and although it is slowing down at 9.8 m/s/s it is initially moving very fast during the first few moments and travels a comparatively large distance.
Subject: Physics (Electricity and Magnetism)
As resistors are added in a purely parallel circuit the the total current of the circuit increases. How can additional resistors increase the current from a power source?
As resistors are added in parallel total resistance of the circuit decreases as the reciprocal sum. As additional branches are added to the circuit, there are more paths for the current. With the voltage being constant in each branch, and the current dividing through each branch, it becomes easier for the total current to flow in the circuit because of these additional paths. Like a highway with more lanes, the overall flow of traffic will be greater.
An automobile traveling at a constant speed is struck head one by a truck of three times the mass traveling at twice the speed. How does the magnitude of the force of the truck on the automobile compare to the magnitude of the force of the automobile on the truck?
The automobile and the truck exert equal forces on teach other. Newton's Third Law indicates all forces exist in pairs of equal magnitude. For a force to exist, two objects must interact with each and they create forces of equal strength. The truck may push the automobile backwards after the collision, but this is an indication of the truck's greater momentum, the forces between the truck and the automobile are equal in size.
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