Which of the following statements correctly describes the models put forth by ptolemy and copernicus to explain the universe? a. both of the models were easy to understand and thus were well received by the public almost instantly. b. through observations, both astronomers presented models where the earth remained stationary. c. the model developed by copernicus was simpler and had less inconsistencies than ptolemy’s model. d. the sun was in the center of ptolemy's model, but the earth was in the center of copernicus' model.

Ptolemy believed that the Earth was motionless and occupied the center of the universe, and that the Sun, the Moon, the planets and the stars revolved around him.

Copernicus said that the center of the universe is close to the Sun.  And orbiting the Sun, in order, are Mercury, Venus, Earth, Moon, Mars, Jupiter and Saturn (Uranus and Neptune were not yet known).

The answer is: C. The model developed by Copernicus was simpler and had fewer inconsistencies than the Ptolemy model.

1 a

2 b

3 b

4 d

5 d

6 d

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