Answer:
Lithium has the lowest electronegativity.
Explanation:
Electronegativity measures the tendency of an atom to attract the bonding pair of electrons. As we move left to right in a period, the number of shell remains same but the number of electron increases(negative charge increases. Hence, electronegativity also increases.
As Lithium is the left most element in this period. It has the lowest electronegativity value which is equal to 0.98.
In order to accelerate the dragster at a speed

, its engine must do a work equal to the increase in kinetic energy of the dragster. Since it starts from rest, the initial kinetic energy is zero, so the work done by the engine to accelerate the dragster to 100 m/s is

however, we must take into account also the fact that there is a frictional force doing work against the dragster, and the work done by the frictional force is:

and the sign is negative because the frictional force acts against the direction of motion of the dragster.
This means that the total work done by the dragster engine is equal to the work done to accelerate the dragster plus the energy lost because of the frictional force, which is

:

So, the power delivered by the engine is the total work divided by the time, t=7.30 s:

And since 1 horsepower is equal to 746 W, we can rewrite the power as
Answer:
Friction between the box and the floor is 25N to the left
Explanation:
There are two forces acting on the box along the horizontal direction:
- The force of push applied by the worker, in the forward direction, F
- The force of friction,
, acting in the opposite direction (backward)
So the net force acting on the box is

According to Newton's second law of motion, the net force on an object is equal to the product between its mass (m) and its acceleration (a), so we can write:

And so

However, in this case the box is moving at constant speed; this means that its acceleration is zero:

Therefore we have:

Which means

And since we are told that

This means that the force of friction is also 25 N:

The angle of reflection is the angle that the reflected ray makes with a line drawn perpendicular to the reflecting surface.
C. The forces on an object traveling at terminal velocity are balanced.