Question

A particle is traveling at a constant speed. This means
A. its position remains constant as time passes
B. it covers equal distance in the equal time interval
C. its acceleration is zero
D. it does not changes its direction of motion

Answer 1

Hint: The ratio of the distance covered by an object over a period of time is known as the speed of the object. It is mainly calculated in $\dfrac{km}{h}$. It is considered to be a scalar quantity. The speed of an object does not specify anything regarding the direction of the object.

Complete step-by-step answer:
The speed of the object is the ratio of the distance and the time taken by the body to cover that distance.
Mathematically,
$S=\dfrac{D}{T}$
Where,
$S$ is the speed
$D$ is the path or distance covered
$T$ is the time taken to cover that distance
Speed is considered to be a scalar quantity. Scalar quantity only has magnitude. They do not give any information about the direction of the motion of the object.
If a body is moving with a constant speed it means that the object is covering an equal length of distance in the same interval of time.
Acceleration of an object is the ratio of the velocity and the time. It is a vector quantity. A vector quantity has magnitude as well as direction.
Mathematically,
$a=\dfrac{v}{t}$
If an object is in motion the acceleration of the body can never be zero.
If an object is traveling it will cover a certain distance with time. So, the position of the body cannot be the same from the same frame of reference.
Thus from the above discussion, we can say that the true statement for the question is
 Option B.

So, the correct answer is “Option B”.

Note: Velocity is the ratio of the displacement and the time taken by the body to displace through its position. Displacement is the shortest path between the initial and the final position of the object. It has a magnitude as well as direction. Therefore the velocity is considered to be a vector quantity. If a person is moving on a circular path it will have some speed but his velocity will be zero. This is due to the reason that the person will reach his initial position after some time and the displacement will be zero.