Differentiate the components of position to get the corresponding components of velocity :


At <em>t</em> = 5.0 s, the particle has velocity


The speed at this time is the magnitude of the velocity :

The direction of motion at this time is the angle
that the velocity vector makes with the positive <em>x</em>-axis, such that

Answer:
A. A resistor alters current and a switch turns current on and off
Explanation:
Resistor is the passive component that reduces the flow of current. Switch is the electrical device that turns on or off the current by closing and opening the electrical circuit.
Thus option A. A resistor alters current and a switch turns current on and off is correct.
Answer:
No work was done.
W = 0
Explanation:
Work is said to be done whenever a force of one newton moves a body of one kilogram through a distance of one meter. Meaning the applied force has to move the body from a point of rest through certain distance.
Work = force × distance
So, in the case of this question, we only have the force been applied, but no distance was covered. Hence, no work was done.
W = 3000× 0 meter
W = 0
Explanation:
To find the resultant force subtract the magnitude of the smaller force from the magnitude of the larger force. The direction of the resultant force is in the same direction as the larger force
Answer:
The electric force on the top charge is
.
Explanation:
Given that,
Electric charges in a thundercloud, 
The distance between charges, d = 2.3 km = 2300 m
Let F is the electric force on the top charge. The electric force is given by the formula as :



or

So, the electric force on the top charge is
. Hence, this is the required solution.