A group of students is making paper airplanes. They think that the kind of paper and the design of the airplane may affect how for each paper airplane fles. The students first test if the kind of paper affects how far the airplane fies. They make
several otrplanes out of different kinds of paper, using
the same design Why is it important that all the airplanes have the same design?

Help please !!

The reason why it is important that all the airplanes have the same design is that the students first test is an experiment to determine the effect of the paper kind on the distance the airplane flies

The first experiment, therefore measures the effect of the independent variable, which is the kind of paper on the dependent variable, which is how far the paper flies

The constant or the factor held constant in the experiment is the design of the airplane, so as to ensure that changes in the distance flown by the airplane are due to the changes in the kind of paper alone

Explanation:

the minimum constant speed at which she can catch the train is 2.7 m/s

given:

acceleration = 0.6

time = 4.5 s

to find:

velocity = ?

formula used:

from 1st kinematic equation we get,

v = u + at

u = initial speed of train = 0 m/s

v = final speed of the train

a = acceleration of the train

t = time

solution:

from 1st kinematic equation we get,

v = u + at

u = initial speed of train = 0 m/s

v = final speed of the train

a = acceleration of the train

t = time

v = 0 + (0.6 × 4.5)

v = 2.7 m/s

the minimum constant speed at which she can catch the train is 2.7 m/s