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A bus is moving at 25m/s. The driver steps on the bakes and the bus stops in 3.0s. What is the averag.....?

A bus is moving at 25m/s. The driver steps on the bakes and the bus stops in 3.0s. What is the average acceleration of the bus while braking? How far did the bus travel in that time period? please show me how to do this question and not just the answer for future questions

Public Comments

1. Acceleration is the change in velocity per unit of time and the units are in m/s^2. So the acceleration of the bus is (-25 m/s) / 3 s = -8.33 m/s^2. This answer is negative since the bus is decelerating. The equation you need for the second part is d = (vi)t + 0.5at^2 where (vi) is the initial velocity of the bus, or 25 m/s. T is time which is 3 seconds, and a is acceleration which we just calculated. If you plug all of those in you get 37.5 meters (remember that acceleration is negative).
2. i guess this is how u should do it: final velocity is zero initial velocity is 25 m/S the time interval is 3.0 S so subtract initial velocity from the final and divide the whole thing by time. that gives u the avg acceleretaion, which will be negative since it's actually deceleration. 0-25 /3 = - 8.3 m/s.s take the acceleretion, sub into the formula that has d (distance) i don't recall the formula now, but there has to be one. since u have everything except d , it would be easy to do the rest jus sub in everything into the formula and solve for d. good luck
3. << What is the average acceleration of the bus while braking? >> Working formula is a = (Vf - Vo)/T where a = acceleration Vf = final velocity = 0 (when bus stops) Vo = initial velocity = 25 m/sec (given) T = stopping time = 3 sec (given) Substituting values, a = (0 - 25)/3 = - 8.33 m/sec^2 NOTE -- the negative sign attached to the acceleration is merely an indication that the bus was (obviously) slowing down when the brakes were applied. << How far did the bus travel in that time period? >> Working formula is X = VoT + (1/2)(a)T^2 where X = distance travelled by bus during the braking period and all the other terms have been previously defined. Substituting appropriate values, X = 25(3) + (1/2)(-8.33)(3^2) X = 37.52 meters Hope this helps.
4. acceleration = change in velocity/ time taken acceleration= (25-0) / 3.0 = 8.3333 m/s2(squared) you do 25-0 because this is the CHANGE in velocity from the speed it was to the speed it is now (stopped ie 0) but of corse its a NEGATIVE acceleration or in other words decelleration maybe try to do the second bit yourself?
5. acceleration = change in velocity / time = 25/3 = 8.33 m/s^2