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anonymous

  • one year ago

acceleration and velocity

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  1. anonymous
    • one year ago
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    A train travels at a velocity of +50 m/s. It takes 80 s to slow down to 5 m/s with constant acceleration. What was its acceleration? A. -0.064 m/s2 B. -0.56 m/s2 C. -8.0 m/s2 D. -10.0 m/s2 On Earth a rock is dropped and falls 4.9 meters just before it hits the ground. How much time did the rock take to fall this distance? A. 0.5 s B. 1.0 s C. 1.2 s D. 2.45 s A girl throws a tennis ball upward with an initial velocity of 4 m/s. What is the maximum displacement of the ball? A. 0.2 m up B. 0.4 m up C. 0.8 m up D. 1.6 m up A car traveling at +30 m/s brakes to exit the highway with an average acceleration of -3 m/s2. About how long is it before the car slows to +5 m/s? A. 5 s B. 8 s C. 10 s D. 18 s A child throws a penny straight down into a wishing well. The penny's initial speed is 2 m/s. If the penny takes 3 seconds to hit the water, how deep is the well? A. 20 m down B. 46 m down C. 50 m down D. 94 m down A spaceship starting from a resting position accelerates at a constant rate of 9.8 meters per second per second. How far will the spaceship travel if its final speed is 1 percent the speed of light (300,000,000 m/s)? A. 3.1 × 106 m B. 2.94 × 108 m C. 7.8 × 1010 m D. 4.6 × 1013 m A model rocket is shot straight upward with an initial velocity of 32 m/s. Its upward acceleration is a constant 6 m/s2. When the fuel is used up at a height of 75 m, what is its velocity? A. 30 m/s up B. 32 m/s up C. 38 m/s up D. 44 m/s up A car starts from a resting position and accelerates at a constant rate of 6 meters per second per second. What is the car's speed after it has traveled 250 meters? A. 41.7 m/s B. 54.8 m/s C. 127.3 m/s D. 1500 m/s If a bicyclist starts from a resting position and reaches a speed of 10 meters per second in 40 seconds, what was his acceleration during this time? Assume he accelerated in a constant way. A. 0.25 m/s2 B. 0.50 m/s2 C. 0.75 m/s2 D. 1.00 m/s2 On Mars a rock falls an unknown vertical distance from a resting position and lands in a crater. If it takes the rock 2.5 seconds to fall, how high is the cliff the rock fell from? Mars' surface gravity is 3.8 m/s2. A. 9.5 m B. 11.9 m C. 15.2 m D. 23.8 m

  2. zephyr141
    • one year ago
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    use these equations \[a=\frac{ v-v_0 }{ t-t_0 }\]\[d=v_ot+\frac{ 1 }{ 2 }at\]\[v^2=v_0^2+2ad\]\[v=v_0+at\]\[d=\frac{ v_0-v }{ 2 }t\]you should be able to solve for all of them with these equations. i think. also you have to look up mar's acceleration due to gravity.

  3. anonymous
    • one year ago
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    (3.8 m/s2)?

  4. anonymous
    • one year ago
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    thank u

  5. anonymous
    • one year ago
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    didn't know the equations to use, do to being absent.

  6. zephyr141
    • one year ago
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    yeah most of these questions can be answered just by using the first kinematic equation. not the equation for acceleration.

  7. zephyr141
    • one year ago
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    good luck.

  8. anonymous
    • one year ago
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    thanks again, im closing the question if i have a problem find an answer ill just ask u

  9. zephyr141
    • one year ago
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    criiipes. ok here's a correction for one of the equations. i just realized i forgot a 2nd power on one of the variables. \[d=v_0t+\frac{ 1 }{2 }at^2\]that's the correct equation.

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