Can a speed of an object be negative?justify
Answers
Answer:
No, speed of a object cannot be negative. Speed is a restricted quantity in physics because it only tells how fast something is going; such quantities are called scalars. Velocity on the other hand, can be negative, because it tells the direction as well as the amount of speed; it belongs to a class of objects called vectors. Formally, speed is the absolute value of velocity.
As an example, consider an object moving at 20 m/s (meters/second) - that is it's speed. But if I say it is moving at 20 m/s West, that is its velocity (speed with direction). Mathematically, to work with velocities, we assign algebraic signs to the four cardinal compass directions: West (-), East (+), South (-) and North (+). So, moving 20 m/s West is written as -20 m/s.
Here is a problem to try to see why direction is important for velocities: Imagine you are watching a train roll past heading due East at 50 m/s (+50 m/s). Inside the train someone throws a ball at 5 m/s first due West and then repeats the throw at the same speed due East. In each case, what velocity would you measure?
Thrown due West (against the train's motion), means the ball's velocity is -5 m/s. So you would see the ball move EAST at 50 - 5 = 45 m/s. Thrown due East (with the train's motion), the ball appears to travel at 50 + 5 = 55 m/s. If I just add the train and ball speeds, I would get |50| + |+/- 5| = 55 in both cases.
Answer:
No it can't be
Explanation:
Hope it helps