Kinetic energy is energy that a body possesses by virtue of being in motion, there for if an object is moving, it has kinetic energy.
Example; A roller coaster sitting on top of hill has potential energy. When it starts to move and is going down the hill, it has kinetic energy. :)
Answer:

where E = electric field intensity
Explanation:
As we know that plastic ball is suspended by a string which makes 30 degree angle with the vertical
So here force due to electrostatic force on the charged ball is in horizontal direction along the direction of electric field
while weight of the ball is vertically downwards
so here we have


since string makes 30 degree angle with the vertical so we will have





where E = electric field intensity
Linear momentum of a truck is 1,50,000 kg.m/s
Explanation:
Linear momentum is the product of the mass and velocity of an object. It is a vector quantity, which have a magnitude and a direction.
Linear momentum is a property of an object which is in motion with respect to a reference point (i.e. any object changing its position with respect to the reference point).
It's SI units are kg.m/s
Linear momentum is a vector quantity.
Linear momentum formula (p) = mass × velocity
Given data mass = 5000 kg ; velocity = 30 m/s
P = 5000 × 30
Linear momentum p= 1,50,000 kg.m/s
I believe the correct answer from the choices listed above is option B. The function of the pulley in this situation is to change the direction of the input force. <span> The </span>pulley<span> simply turns a force in one direction into a force in another direction. Hope this answers the question. Have a nice day.</span>