Which statements about braking a car are true?
the greater the kinetic energy of a car, the longer it takes for the car to stop.
the lower the kinetic energy of a car, the longer it takes for the car to stop.
if the speed of a car doubles, the car’s kinetic energy and braking distance quadruple.
if the speed of a car doubles, the car’s kinetic energy and braking distance remain the same.

C. If the speed of a car doubles, the car’s kinetic energy and braking distance quadruple. And A.The greater the kinetic energy of a car, the longer it takes for the car to stop.

The greater the kinetic energy of a car, the longer it takes for the car to stop.

If the speed of a car doubles, the car’s kinetic energy and braking distance quadruple.

Explanation:

The kinetic energy is given by the formula,

½ mv²

where m is the mass and v is the velocity.  

So when the velocity or speed doubles the kinetic energy will quadruple.  

A car moving with high kinetic energy has a high speed or velocity therefore it is going to take more time to reduce the higher speed and bring the car to a halt.  

out of these options:

ability to burn paper

pure sodium reacting violently with water

the boiling point of water

helium does not tend to react with anything

i would say this is a physical property:

helium does not tend to react with anything

why? :

i said helium does not tend to react with anything because well, it reacts to ! but ability to burn paper, pure sodium reacting violently with water, & the boiling point of water are chemical or

physical properties: the properties of a substance that can be observed without changing the chemical makeup of the substance

chemical properties: properties of a substance relating to the chemical nature and reactivity of the substance

1.solid

2.carbon dioxide

3.helium