Answer:
Approximately
, assuming that
.
Explanation:
Let
and
denote the mass and acceleration of Spiderman, respectively.
There are two forces on Spiderman:
- Downward gravitational attraction from the earth:
. - Upward tension force from the strand of web
.
The directions of these two forces are exactly opposite of one another. Besides, because Spiderman is accelerating upwards, the magnitude of
(which points upwards) should be greater than that of
(which points downwards towards the ground.)
Subtract the smaller force from the larger one to find the net force on Spiderman:
.
On the other hand, apply Newton's Second Law of motion to find the value of the net force on Spiderman:
.
Combine these two equations to get:
.
Therefore:
.
By Newton's Third Law of motion, Spiderman would exert a force of the same size on the strand of web. Hence, the size of the force in the strand of the web should be approximately
(downwards.)
Answer:
The correct statement is "The electric field is directed toward the electron and has a magnitude of
".
Explanation:
According to Coulomb's law, the magnitude of the electric field due to a static point charge q at a point r distance away from it is given by

- k is the Coulmob's constant.
The direction of the electric field along the line joining the charge and the point where electric field is to be found and it is directed from positive charge to negative charge.
Conventionally, we assume a positive test charge placed at the point where electric field is to be found, the test charge has very small charge such that its charge does not affect the electric field due to the given charge.
The charge on the electron = -e.
The electric field due to an electron is given by

The direction of this electric field is from positive test charge, placed at the point where electric field is to be found, towards the electron along the line joining the two.
Thus, the correct statement is "The electric field is directed toward the electron and has a magnitude of
".
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