Question

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 A

Car B

Car C

Car D

Car E

Answer 1

Car D

Step-by-step explanation:

The mass of the car is given the same. The initial velocities are also given. eventually all the cars come to a stop. The finish line would be crossed first by the fastest car. But If all the cars decelerate at the same rate then, we can find out the time taken to come to a full stop by first equation of motion,

`v-u = at`

final velocity, v = 0

`t \propto u` if a is same for all cars.

Car D has maximum speed ( 895 m/s). So, Car D will take the maximum time to come to a stop.

Answer 2

Car C

Step-by-step explanation:

It is given that,

Five race cars speed toward the finish line at the Jasper County Speedway. The mass of each car has same mass. The speed of all cars are given as :

Car A = 890 m/s

car B = 850 m/s

Car C = 790 m/s

Car D = 895 m/s

Car E = 870 m/s

The distance is constant because the finish line is same for all cars. The speed of an object is given by the total distance covered divided by total time taken i.e.

`s=(d)/(t)`

Where

d = distance

t = time required by the car to come to a full stop

`t=(d)/(s)`

So, time taken is inversely proportional to the speed of the car. The car having less speed will take maximum time to come to stop. Hence, car C will require longest time to come to a full stop.