Please help me

5.02s    

Explanation:

Given parameters:

Initial speed  = 25m/s

Final speed  = 30m/s

Distance  = 138m

Unknown:

Time taken for the body to accelerate  = ?

Solution:

We start by finding the acceleration of the body using the expression below;

           v² = u² + 2as

v is the final velocity

u is the initial velocity

a is the acceleration

s is the distance

            30²  = 25²  + 2(a ) x 138

           900 = 625 + 276a

            900 - 625  = 276a

                275 = 276a

                   a = 0.996m/s²

Now to find the time taken, use the expression below;

            v  = u + at

t is the unknown time;

            30 = 25 + 0.996t

               5  = 0.996t

               t = 5.02s    

i think the answer would be b

force is mass*acceleration.

we have a very small mass: 11.4*0.001 kg

if we want 0.035n of force, we need an acceleration:

0.035 = 11.4*0.001*a

a = 0.035/(11.4*0.001) m/s^2