In a science fiction novel two enemies, Bonzo and Ender, are fighting in outer spce. From stationary positions, they push against each other. Bonzo flies off with a velocity of 1.3 m/s, while Ender recoils with a velocity of -3.1 m/s. Determine the ratio mBonzo/mEnder of the masses of these two enemies?

2.461

Explanation:

Let mass of Bonzo = m1

Mass of Ender =m2

When they push eachother from stationary position

Initial velocity of Bonzo = Vib=0 m/s

Final velocity of Bonzo = Vfb= 1.3 m/s

Initial velocity of Ender = Vie= 0 m/s

Final velocity of Ender = Vfe= -3.1 m/s

We know initial momentum = final momentum

==> m1Vib+m2Vie = m1Vfb+m2Vfe

==> 0+0= m1×1.3 +m2×(-3.1)

==> 1.3m1-3.1m2=0

==> 1.3 m1 = 3.2 m2

==> m1/m2 = 3.2/1.3

==> m1/m2 = 2.461

gravity

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