67. The formula to calculate a rate is r = Which of the following is a equivalent formula?
c) d =
a) d = r *t
b) d = r +t
d) none of the above

a) d = r *t

Explanation:

The equivalent formula for calculating rate is given as:

                 d = r *t

Where d is the amount of substance, r is the rate and t is the time taken.

The rate of process is the amount or quantity attained per unit of time.

It is usually expressed as;

           r  =

So, the other variant will be d = r *t

the five characteristics of adolescence are biological growth and development, and undefined status, increased decision making, increased pressure and the search of self.

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