The car's speed was zero at the beginning of the 12 seconds,
and 18 m/s at the end of it. Since the acceleration was 'uniform'
during that time, the car's average speed was (1/2)(0 + 18) = 9 m/s.
12 seconds at an average speed of 9 m/s ==> (12 x 9) = 108 meters .
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That's the way I like to brain it out. If you prefer to use the formula,
the first problem you run into is: You need to remember the formula !
The formula is D = 1/2 a T²
Distance = (1/2 acceleration) x (time in seconds)²
Acceleration = (change in speed) / (time for the change)
= (18 m/s) / (12 sec)
= 1.5 m/s² .
Distance = (1/2 x 1.5 m/s²) x (12 sec)²
= (0.75 m/s²) x (144 sec²) = 108 meters .
Answer:
120
Work :
W = Fd (work = force x distance)
Force :
F = W/d
Distance :
d = W/F
Kinetic energy is the energy possessed by an object when that object is moving in space. The higher the mass of an object or higher the speed of an object the higher the kinetic energy will be.
So to calculate the Kinetic Energy we can use the following formula
K.E=(1/2)*m*v^2
Inserting the values in formula gives:
K.E=1/2*7.26*2^2
14.52J
This is the final answer which gives the kinetic energy of the ball.
I would say your answer to this question would be D
You can only determine the speed since the only info we know is how much you ran in how long of a time.
