Physics

posted by Naomi

A car, moving along a straight stretch of highway, begins to accelerate at 0.0442 m/s^2. It takes the car 30.8 s to cover 1 km. How fast was the car going when it first began to accelerate?
Answer in units of m/s.

I tried converting 30.8 km/sec to m/s then subtracting 0.0442, but I got -0.0134, and it can't be a negative. I've also tried the answers 30799.558, 13.4, and 0.0134 but my online homework sheet has said they are all wrong. Thanks for the help!

  1. jzee11

    Here what i did.
    a=0.0442 m/s^2
    t1=30.8 s
    d=1 km =1000 m.
    find the initial velocity (speed)=Vo when car starts accelerating.

    From basic equation of acceleration,
    a = dv/dt = (V1-Vo)/(t1-t0) ; t0= 0s.

    Vo = V1 - a.t1

    missing V1=d/t0 = 1000/30.8 = 32.46 m/s.
    Then, Vo = 32.46 - (0.0442)(30.8)
    =31.1 m/s

    tell me answer is correct or not.

Respond to this Question

First Name

Your Answer

Similar Questions

  1. Physics

    On its way to Peace River, Alberta, a car enters a passing zone on the highway. The car is 25.0 m behind a truck and both vehicles are travelling at 41.0 m/s. The car accelerates uniformly to overtake the truck and after the car has …
  2. physics

    Two cars are traveling at the same constant speed v. Car A is moving along a straight section of the road, while B is rounding a circular turn. Which statement is true about the acceleration of the cars?
  3. physics

    A car, moving along a straight stretch of highway, begins to accelerate at 0.0218 m/s 2 . It takes the car 86 s to cover 2 km. How fast was the car going when it first began to accelerate?
  4. physics

    A certain car can accelerate from rest to the speed v in time T seconds. (a) If the power output of the car remains constant, how long does it take for the car to accelerate from v to 3v, in terms of T?
  5. Physics

    9)A car, moving along a straight stretch of highway, begins to accelerate at 0.0153 m/s 2 . It takes the car 29.2 s to cover 1 km. How fast was the car going when it first began to accelerate?
  6. Physics B

    A car, moving along a straight stretch of highway, begins to accelerate at 0.0261 m/s2. It takes the car 48.6 s to cover 1 km. How fast was the car going when it first began to accelerate?
  7. Physics

    A car, moving along a straight stretch of highway, begins to accelerate at 0.0235 m/s 2 It takes the car 67.8 s to cover 1 km.How fast was the car going when it first began to accelerate?
  8. Physics

    A car, moving along a straight stretch of high- way, begins to accelerate at 0.014 m/s2. It takes the car 23.2 s to cover 1 km. How fast was the car going when it first began to accelerate?
  9. Physics

    A car, moving along a straight stretch of high- way, begins to accelerate at 0.0377 m/s2. It takes the car 34.3 s to cover 1 km. How fast was the car going when it first began to accelerate?
  10. Physics

    A car is behind a truck going 18 m/s on the highway. The car's driver looks for an opportunity to pass, guessing that his car can accelerate at 0.6 m/s2 and that he has to cover the 20-m length of the truck, plus 10-m extra space at …

More Similar Questions