To help pick to up the metal and place it in a incinerator <span />
Answer:

Explanation:
Take at look to the picture I attached you, using Kirchhoff's current law we get:

This is a separable first order differential equation, let's solve it step by step:
Express the equation this way:

integrate both sides, the left side will be integrated from an initial voltage v to a final voltage V, and the right side from an initial time 0 to a final time t:

Evaluating the integrals:

natural logarithm to both sides in order to isolate V:

Where the term RC is called time constant and is given by:

Answer:
The correct option is (b).
Explanation:
We need to find the work done to increase the speed of a 1 kg toy car by 5 m/s.
We know that, the work done is equal to the kinetic energy of an object i.e.

So, 12.5 J of work is done to increase the speed of a 1.0 kg toy car by 5.0 m/s.
Answer:
D)Not enough information
Explanation:
According to Pascal's principle, the pressure exerted on the two pistons is equal:

Pressure is given by the ratio between force F and area A, so we can write

The force exerted on each piston is just equal to the weight of the corresponding mass:
, where m is the mass and g is the gravitational acceleration. So the equation becomes

Now we can rewrite the mass as the product of volume, V, times density, d:

We also know that 
So we can further re-arrange the equation (and simplify g as well):


We are also told that block B has bigger volume than block A:
. However, this information is not enough to allow us to say if the fraction on the right is greater than 1 or smaller than 1: therefore, we cannot conclude anything about the densities of the two objects.
Because mass and distance determine gravity, so the more mass you have, the more gravity.