Answer:
Far point.
Explanation:
The maximum distance up to which the normal eye can see objects distinct and clear is called the far point of the eye. It is infinity for a normal eye.
Answer:
Current, I = 3.57A
Explanation:
A current of I amperes means that I Coulombs of charge flows through the conductor (heating coil) per second.
Therefore, in time t, the total charge (Q) passing through any point in which the current (C) flows will be given by the equation;
Q = It
Where; Q is the charge in coulombs; I is the current in amperes; t is the time in seconds.
From the question, we were given the following parameters;
Q = 25C, t= 7secs and I =?
From the equation, Q = It
We make current, I the subject of formula;
Thus, I = Q/t
Substituting into the equation;
I = 25/7
I = 3.57Amp.
Complete Question
An infinite sheet carries a uniform, positive charge per unit area. The electric field produced by the sheet is represented by parallel lines drawn with a density N lines per m2 that are perpendicular to and away from the sheet. The charge per unit area on the sheet is doubled. How should the density of the electric field lines be changed?
A It should stay the same
B It should be quadrupled.
C It should be quintupled
D It should be doubled.
E It should be tripled
Answer:
Option D is the correct option
Explanation:
Generally electric field is mathematically represented as

Where
is the charge per unit area (Charge density )
From the question we are told that
is doubled hence the
Looking the equation above we see that the value of the electric field will also double given that it is directly proportional to the charge density
Answer:
2.1 s
Explanation:
The motion of the ball is a projectile motion. We know that the horizontal range of the ball is

And that the initial speed of the ball is

at an angle of

So, the horizontal speed of the ball (which is constant during the entire motion) is

And since the horizontal range is 50 m, the time taken for the ball to cover this distance was

which is the time the ball spent in air.
Answer:
a) 2 m/s
b) i) 
ii) 
Explanation:
The function for distance is 
We know that:
Velocity = 
Acceleration = 
To find speed at time t = 0, we derivate the distance function:

Substitute t = 0 in velocity function:

Velocity at t = 0 will be 2 m/s.
To find the function for Kinetic Energy of the box at any time, t.

We know that 

