Because it generates enough momentum to keep the train going with out really having to speed up
The acceleration of the boxes depends on the mass and weight.
we have a mass of 7 and 8 kilograms
if it took 25 N force to move box A, then you would take 25 and multiply by 8 then divide by 2.
It will leave you with 100 N.
finally take the sq rt of 100 to get 10
Explanation:
First, we need to determine the distance traveled by the car in the first 30 minutes,
.
Notice that the unit measurement for speed, in this case, is km/hr. Thus, a unit conversion of from minutes into hours is required before proceeding with the calculation, as shown below

Now, it is known that the car traveled 40 km for the first 30 minutes. Hence, the remaining distance,
, in which the driver reduces the speed to 40km/hr is
.
Subsequently, we would also like to know the time taken for the car to reach its destination, denoted by
.
.
Finally, with all the required values at hand, the average speed of the car for the entire trip is calculated as the ratio of the change in distance over the change in time.

Therefore, the average speed of the car is 50 km/hr.
<span>The correct answer should be B) 63.55. That's because the most precise number is 63.546, but you would write 55 because 46 is rounded that way in the equation. The others are a bit higher, while E is a completely different element, Iodine. This isn't the most precise piece of data because in reality there would be a slight differentiation of +- 0,003u</span>
Answer: EL ZINC ES EL ELEMENTO PURO PORQUE NO HA REACCIONADO CON NINGÚN OTRO METAL O NO METAL. EL SULFURO DE ZINC ES UN COMPUESTO PORQUE HA REACCIONADO CON EL AZUFRE PARA HACER EL COMPUESTO.
english:
ZINC IS THE PURE ELEMENT BECAUSE IT HAS NOT REACTED WITH ANY OF OTHER METAL OR NONMETAL. ZINC SULPHIDE IS A COMPOUND BECAUSE IT HAS REACTED WITH SULPHUR TO MAKE COMPOUND.