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Matthew is cycling of a Speed of 4 meters per second . When he starts down the hill the bike wheb he starts down a hill , the bike accelerates at a rate of 0.4 m/s squared the vertical distance from the top of the hill to the bottom of the hill is 25 m is the equation d(t)=v0t+1/2 at^2 two find how long it will take mathew to ridedown the hill

2 Answers

4 votes

Answer:

It’ll only take Mathew 5 seconds to ride his bike down the hill.

Explanation:

User Pkaleta
by
5.1k points
5 votes

Answer:

Mathew will take 5 seconds to ride down the hill.

Explanation:

Given equation is:
d(t)= v_(0)t +(1)/(2)at^2

Matthew is cycling of a speed of 4 meters/second. So,
v_(0)= 4 m/s

When he starts down a hill, the bike accelerates at a rate of 0.4 m/s². So,
a= 0.4 m/s^2

The vertical distance from the top of the hill to the bottom of the hill is 25 meters. So,
d(t)= 25 meters.

Plugging the values into the above equation, we will get......


25= 4t+(1)/(2)(0.4)t^2\\ \\ 25= 4t+0.2t^2\\ \\ 0.2t^2+4t-25=0

Using quadratic formula, we will get.......


t= (-4\pm √(4^2-4(0.2)(-25)))/(2(0.2))\\ \\ t=(-4\pm √(16+20))/(0.4)\\ \\ t=(-4\pm √(36))/(0.4)=(-4\pm 6)/(0.4)\\ \\ t=(-4+6)/(0.4)=(2)/(0.4)=5\\ \\or\\ \\ t=(-4-6)/(0.4)=(-10)/(0.4)=-25

(Negative value is ignored as the time can't be negative)

So, Mathew will take 5 seconds to ride down the hill.

User Marcelorodrigues
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5.5k points