If a vehicle is moving with a velocity of 20 m/s and it comes to a stop after 4 seconds, we can assume that the vehicle undergoes constant deceleration (negative acceleration) until it reaches a velocity of 0 m/s.
To find the final velocity, we can use the formula for uniformly accelerated motion:
vf=vi+atv_f = v_i + atvf=vi+at
where:
- vfv_fvf is the final velocity,
- viv_ivi is the initial velocity,
- aaa is the acceleration, and
- ttt is the time.
In this case, the initial velocity (viv_ivi) is 20 m/s, the final velocity (vfv_fvf) is 0 m/s, and the time (ttt) is 4 seconds.
Since the vehicle is decelerating, the acceleration (aaa) will be negative. We'll denote it as −a-a−a.
Plugging the given values into the formula, we have:
0=20+(−a)⋅40 = 20 + (-a) cdot 40=20+(−a)⋅4
Simplifying the equation:
0=20−4a0 = 20 - 4a0=20−4a
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