N, or Neutons are a common way to measure force
Answer:
The work done to lift the counterweight equals the potential energy acquired
Explanation:
since this is vertically applied force on the counterweight, and the distance the force is displacing the counterweight is in the same direction as the applied force, it equals the gained potential energy
Vf = Vi + at
Vf = 0 + 5.4•28
= 151.2m/s..
not sure if its right
Answer:
<em>We need to (at least) apply a force of 9.8 N to move the block</em>
Explanation:
<u>Second Newton's Law</u>
If a net force
different from zero is applied to an object of mass m, then it will move at an acceleration a, given by

If we apply a force F to an object placed on a rough surface, the only way to make it move is to beat the friction force which is given by

Where
is the static friction coefficient and
is the normal force exerted by the table to the object. Since there is no motion in the vertical direction the normal force equals the weight of the object:

The friction force is

Thus, we need to (at least) apply a force of 9.8 N to move the block
Answer:
(e) The particles move apart with a velocity that increases for a while and then becomes constant.
Explanation:
Each particle feels a repulsive (because they have same sign of charge) electric force from the each other:

and

So each particle feels a repulsive force proportional to the quadratic inverse of the distance.that means that the charges begin to move away, and the further away they are from each other, the force (and therefore the acceleration) decreases, at a rate inversely proportional to the square of the distance. Theoretically this acceleration will never be zero, but in practice it will at some point reach a value very close to zero. Then the speed will grow for a while and when the acceleration has reached almost zero, the speed will practically remain constant.