How much work must they do to stop a car that is moving four times as fast?

Compared to some original speed, how much work must the brakes of a car supply to stop a four-times-as-fast car? How will the stopping distance compare? A four-times-as-fast car has 16 times as much KE and will require 16 times as much work to stop, and 16 times as much stopping distance.

Which of the following is an example where a force is exerted on an object without doing work on the object?

Cite an example where a force is exerted on an object without doing work on an object. A force is needed to hold a barbell overhead, but this force does no work on the barbell while the bar bell is at rest.

What is the efficiency of a machine that miraculously converts all the input energy to useful output energy?

21. What is the efficiency of a machine that miraculously converts all the input energy to useful output energy? 21. Efficiency would be 100\%.

When the speed of a moving car is doubled How much more kinetic energy does it have?

four times
If you double the speed of an object, the kinetic energy increases by four times. The word “kinetic” comes from the Greek word “kinesis” which means motion. Kinetic energy can be passed from one object to another in the form of a collision.

Can a machine multiply input force?

A machine can multiply force and it can multiply distance. However, it cannot multiply input energy because this would violate the law of conservation of energy.

How does the energy work theorem apply to stopping vehicles?

9.6 Work-Energy Theorem A car moving at twice the speed of another has four times as much kinetic energy, and will require four times as much work to stop. The frictional force is nearly the same for both cars, so the faster one takes four times as much distance to stop.

What are you exerting when you do work?

When do you work? When you exert a force in an object that causes the object to move some distance in the same direction as the exerted force.

When a simple machine multiplies force it decreases?

When a simple machine multiplies force, it decreases the distance moved.

When the speed of your car is doubled by what factor?

When the speed of your car is doubled, by what factor does its kinetic energy increase? Therefore when you double the velocity, that value is then squared. Therefore your kinetic energy is increased by 4 times the original amount.

Why does doubling speed quadruple range?

The simple answer is that in the equation for the Kinetic Energy the velocity is ‘squared’. If you double the velocity, the overall quantity is quadrupled.

How does a machine multiply force?

Ideal simple machine multiplied by the load force. multiplied by the applied force. This can be calculated from the geometry of the machine. For example, the mechanical advantage and distance ratio of the lever is equal to the ratio of its lever arms.

What is the stopping force?

The stopping force acts against the direction of the car’s motion. The forces →FG and →N are perpendicular to the stopping force →Fb They have the same magnitude and opposite directions thus their net force is zero and the acceleration of the car in the direction of the axis y is zero, too.