Question

How long does it take for an object to decrease its speed by 60 m/s if the acceleration is -4m/s^2?

Answer 1

To determine how long it takes for an object to decrease its speed by a certain amount, we can use the equation of motion:

$v_f=v_i+at$

where:

• $v_f$ is the final velocity
• $v_i$ is the initial velocity
• $a$ is the acceleration
• $t$ is the time

In this case, the initial velocity is not given, but we can assume that the object is initially moving with a positive velocity. Since the acceleration is negative (-4 m/s²), it indicates that the object is slowing down.

Let's solve for the time it takes for the object to decrease its speed by 60 m/s:

Given: $v_f=0$ m/s (final velocity, since the object comes to rest) $v_i$ = initial velocity (unknown) $a=-4$ m/s² (acceleration) $\Delta v=v_f-v_i=-60$ m/s (change in velocity)

Substituting the values into the equation of motion, we have:

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