Answer:
Explanation:
1 ) Momentum of a race car = mass of car x velocity of car . During a collision , an external force acts on the car which changes the momentum of the car in the direction in which force acts .
2 )
The momentum of the car decreases as external force acts against the momentum . Sometimes when external force is very high , direction of momentum is reversed .
3 ) Impulse is force x time of action of force . Generally time of action of force in large collision is very small . so it is calculated very carefully .
Impulse = change in momentum .
4 ) The type of collision is inelastic . In this type of collision , car crashes into safer barrier , sticks to it . It does not rebound from the barrier . In case of elastic collision , rebound creates large impulse creating huge damage to the car .
Answer:
<em>To reverse the direction of an electric current, we simply reverse the voltage either automatically with the help of some switching circuitry or manually by changing the voltage source terminals connection. </em>
Explanation:
For electric current to flow, there must be a potential difference, usually referred to as the voltage. The electric current flow is analogous to the flow of water under the action of a pump, through a series of pipe connections. The voltage is similar to the driving action of the pump, and current flows the same way water flows. The resistance due to drag on the pipe wall is equivalent to electric resistance. For current to flow in the reverse direction, the voltage or rather, the potential difference is changed, causing the current to flow in the opposite direction. This can be done by switching the terminals of the voltage source, or by automatic means. The automatic switching can be done with a transistor based circuitry.
<span>The different colors of visible light have different wavelengths.
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