162k views
4 votes
Which statement correctly describes the differences between positive and negative acceleration? Positive acceleration describes a change in speed; negative acceleration describes no change in speed. Positive acceleration describes no change in speed; negative acceleration describes a change in speed. Positive acceleration describes an increase in speed; negative acceleration describes a decrease in speed. Positive acceleration describes a decrease in speed; negative acceleration describes an increase in speed.

User Rick Falck
by
7.9k points

2 Answers

5 votes

The correct answer is - Positive acceleration describes an increase in speed; negative acceleration describes a decrease in speed.

User Jtimperley
by
8.1k points
3 votes

Answer:

Positive acceleration describes an increase in speed; negative acceleration describes a decrease in speed.

Step-by-step explanation:

Acceleration is defined as:


a=(v-u)/(\Delta t)

where

v is the final velocity

u is the initial velocity


\Delta t is the time taken for the change in velocity to occur

The value of
\Delta t is always positive, so the sign of the acceleration depends on the numerator. More specifically, we have two situations:

- if
v > u, then it means that the final velocity is greater than the initial velocity, so the acceleration is positive and the speed is increasing

- if
v < u, then it means that the final velocity is smaller than the initial velocity, so the acceleration is negative and the speed is decreasing

User Mangoose
by
8.7k points

No related questions found