An isolated system contains two objects with charges q1q1 and q2q2. If the charge on object 1 is doubled, what is the charge on object 2? g

The new charge on the second object is q₂ - q₁

Explanation:

Given;

charge on the first object,  q₁

charge on the second object, q₂

Since there is no external force on isolated system, the total charge in the system is given by;

Q = q₁ + q₂

q₂ = Q - q₁

When the charge on object 1 is doubled, q₁' = 2q₁

let q₂' be the new charge on object 2

q₂' = Q - q₁'

q₂' = (q₁ + q₂) - 2q₁

q₂' = q₁ + q₂ - 2q₁

q₂' = q₂ - q₁

Therefore, the new charge on the second object is q₂ - q₁

b. lifting dumbbell weight at 20-degree angle from the body after a 45-degree angle

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