Question #4f1eb

1 Answer
Feb 24, 2017

Answer:

Explanation:

Explanation:

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We know the ball is thrown upwards in a initial velovity of #15.8 m/s#

So, #u=15.8 m/s#

When the ball reaches its maximum height, it has a velocity of #0 m/s#

So, #v=0 m/s#

Let the maximum height be #x#

The gravitational force that makes the ball slow down till it reaches its maximum height

So, #a=-9.8 m/s#

Now, we have to find the time to reach its maximum height

We have our values

#color(orange)(u=15.8 m/s#
#color(orange)(v=0 m/s#
#color(orange)(a=-9.8 m/s#

We can use one of the Kinematic equations

#color(blue)(v=u+at#

#rarr0=15.8+(-9.8t)#

#rarr0=15.8-9.8t#

#rarr9.8t=15.8#

#rarrt=15.8/9.8#

#color(green)(rArrt=1.61 s#

We can use this value to find the maximum height (#x#) using another Kinematic equation

#color(brown)(x=ut+1/2at^2#

#rarrx=(0*1.61)+(1/2*(-9.8)*1.61^2)#

#rarrx=1/2*(-9.8)*2.59#

#rarrx=(-9.8)*1.29#

#color(green)(rArrx=-12.64m#

As height cannot be negative, #x=12.64m#

Hope this helps! :)