Answer:
E=
Explanation:
We are given that
Charge on ring= Q
Radius of ring=a
We have to find the magnitude of electric filed on the axis at distance a from the ring's center.
We know that the electric field at distance x from the center of ring of radius R is given by
Substitute x=a and R=a
Then, we get
Where K=
Hence, the magnitude of the electric filed due to charged ring on the axis of ring at distance a from the ring's center=
14 m/s or 50km/h. See the details in the attached picture.
Newton's second law states that the resultant of the forces applied to an object is equal to the product between the object's mass and its acceleration:
where in our problem, m is the mass the (child+cart) and a is the acceleration of the system.
We are only concerned about what it happens on the horizontal axis, so there are two forces acting on the cart+child system: the force F of the man pushing it, and the frictional force
acting in the opposite direction. So Newton's second law can be rewritten as
or
since the frictional force is 15 N and we want to achieve an acceleration of
, we can substitute these values to find what is the force the man needs:
Answer:
The answer is A
Explanation:
Lightning is formed by electrons in the air
So far, since you moved into the apartment until the end of this much of the story, you haven't done ANY work on the dresser yet.
I'll admit that you pushed, groaned and grunted, sweated and strained plenty. You're physically and mentally exhausted, you're not interested in the dresser at the moment, and right now you just want to snappa cappa brew, crash on the couch, and watch cartoons on TV. But if you've done your Physics homework, you know you haven't technically done any <u><em>work</em></u> yet.
In Physics, "Work" is the product of Force times Distance.
Since the dresser hasn't budged yet, the Distahce is zero. So no matter how great the Force may be, it's multiplied by zero, so the <em>Work is zero</em>.
