Five race cars speed toward the finish line at the jasper county speedway. the table lists each car’s speed in meters/second. if each car has the same mass, which car will require the longest time to come to a full stop?

car a car b car c car d car e
890 m/s 850 m/s 790 m/s 895 m/s 870 m/s

CAR D

Explanation:

As we know that all cars have same mass so the deceleration of the car that will reduce its speed to rest is given as

so it will be same for all cars.

Now we know by kinematics as

so time taken by it to stop is given as

here since final speed of all cars is zero so we can say that more initial speed of car will take more time to stop the car.

So longest time will take by Car D

force is based upon mass and acceleration.the statement is not always true.

it can be explained from newton's second law of motion.

as per newton's second law of motion the rate of change of momentum is directly proportional to the applied force and takes place along the direction of force.

mathematically it can be written as -

                                              ⇒      

here   k is the proportionality constant whose value is 1.

                                                            [a is the acceleration=dv/dt]

hence we see that force not only depends on mass and acceleration but also on velocity and rate of change of mass. force f will depend on mass and acceleration only when mass is constant.

hence the statement that force is based upon mass and acceleration is false.