A. The distance between B and a is 450 km. A and B start from a and B at the same time and run in opposite directions. It is known that the speed of a is 120 km / h and that of B is 80 km / h. After t hours, the distance between two vehicles is 50 km, then the value of T is () A. 2 or 2.5B. 2 or 10C. 10 or 12.5d. 2 or 12.5

A. The distance between B and a is 450 km. A and B start from a and B at the same time and run in opposite directions. It is known that the speed of a is 120 km / h and that of B is 80 km / h. After t hours, the distance between two vehicles is 50 km, then the value of T is () A. 2 or 2.5B. 2 or 10C. 10 or 12.5d. 2 or 12.5

(1) When car a and car B do not meet, according to the meaning of the question, we get 120t + 80t = 450-50, and the solution is t = 2; (2) when the two cars meet and the distance between them is 50km, according to the meaning of the question, we get 120t + 80t = 450 + 50, and the solution is t = 2.5

A. The distance between B and a is 450 km. A and B start from a and B at the same time and run in opposite directions. It is known that the speed of a is 120 km / h and that of B is 80 km / h. After t hours, the distance between two vehicles is 50 km, then the value of T is ()
A. 2 or 2.5B. 2 or 10C. 10 or 12.5d. 2 or 12.5

(1) When car a and car B do not meet, according to the meaning of the question, we get 120t + 80t = 450-50, and the solution is t = 2; (2) when the two cars meet and the distance between them is 50km, according to the meaning of the question, we get 120t + 80t = 450 + 50, and the solution is t = 2.5

A small car moves in a straight line with uniform acceleration for 5 seconds. Given that the displacement in the first 3 seconds is 12 meters and that in the last 3 seconds is 18 meters, what is the acceleration of the car in these 5 seconds? & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; the answer is 1 & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp;

It is known that the displacement in the first three seconds is 12 m, and that in the last three seconds is 18 m. The results show that: (1) the displacement in the first three seconds: the displacement in the first, second and third seconds; (2) the displacement in the last three seconds: the displacement in the third, fourth and fifth seconds according to the instantaneous velocity in the middle = the average velocity; (1) the intermediate velocity in the third second is 1

When a 25kW car is driving on a straight road, the speed on the car is 100km / h, and the average resistance of the car is calculated
Please write down the answer

f=p/v=25k/100=250N