Physics again. Please help me answer.

Question

More questions. Hope you can answer this. First one to answer gets Best answer.

1. A car started from a rest and accelerated at 9.54m/s square for 6.5 seconds. How much distance was covered by the car?

2. A paper airplane is thrown horizontally with a velocity of 20 mph. The plane is in the air for 7.43 seconds before coming to a stand still on the ground. What is the acceleration on the plane?

3. A pile driver drops from a height of 35 meters before landing on a piling. What is the speed of the driver when it hit the piling?

Thx again so much, if you guys can answer these questions.!

Answer 1

the answer are here take....

1)    you should know the formula. speed = distance / time.

       in the above question, Speed = 9.54 m/s square. & Time =  6.5 s

    9.54 = distance / 6.5   ( we must have the variable on 1 side and    

                                         the constants on the other )

    9.54 * 6.5 = distance

    therefore, Distance = 62.01

2)          the formula for acceleration is ( acceleration = change in  

                                                           velocity / time taken )

             In this question, velocity = 20mph    &    time = 7.43s

                   according to the formula, velocity and time is give.

  

               thus acceleration = 20 / 7.43

                                         = 2.692 ( round of to 3 significant digits )

3)            the question is not clear, because to find out the speed, we must have 2 values given. but in this case, only the distance is given, and not the time.

thank you

by the way i deserve that 10 points.

c ya

byee...

    

Answer 2

1. D= V_initial*t + (1/2)a*t^2

2. A = (v2-v1)/t

3. You can use conservation of energy to solve this:

Eg(initial) + Ek(initial) = Eg(final)+Ek(final)

m(9.81)(35) + 0 = 0 + 1/2m*v^2

Solve for V. You will notice the masses cancel out of your equation. To you this should make sense because objects - no matter the mass - accelerate to the ground at the same rate: that of the acceleration due to gravity.

I will not give you the answers. You can do that yourself.

Answer 3

acceleration is measures in m/s/s

i can't actually help u i just like picking up on technicalities!