Surface? What is the mass of an object that experiences a gravitational force of 700 N near the Earth's surface

70kg

Explanation:

Given parameters:

Gravitational force  = 700N

Unknown:

Mass of the person = ?

Solution:

The weight is gravitational force on the person and can be expressed as;

        W = mg

m is the mass

g is the acceleration due to gravity  = 10m/s²

 So;

        700 = m x 10

            m  = 70kg

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