Which of the following statements is correct?
a) The basic unit of time is second.
b) Every object’s motion is uniform.
c) Two cars move for 5 minutes and 2 minutes respectively. The second car is faster because it takes less time.
d) The speed of a car is expressed in km/h
Answers
The first statement is true
Answer:
The Correct Option is,
a) The basic unit of time is second
As per SI, The Standard unit of time is second. And Hours, Minutes are practical units of time.
Every object’s motion is uniform
This statement is wrong because, A body is said to be in Uniform motion if it covers equal distances in equal intervals of time, however small or large the intervals of time may be.
Two cars move for 5 minutes and 2 minutes respectively. The second car is faster because it takes less time
This statement is wrong. Speed is dependent on both distance and time taken to cover the distance. Speed is the measure of fastness. Since, The statement doesn't talk about distance covered by cars. It's wrong to say which car is faster. It's not possible to determine the faster car.
The speed of a car is expressed in km/h.
Practically its correct that, Speed of a car as expressed in the Speedometer is generally in km/h or mph. But According to SI system, Speed should be expressed in m/s as its the standard unit.