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riadik2000 [5.3K]

2 years ago

8

If a rock is thrown upward on the planet mars with a velocity of 14 m/s, its height (in meters) after t seconds is given by h =

14t − 1.86t2. (a) find the velocity of the rock after two seconds.

1 answer:

crimeas [40]2 years ago

6 0

<u>Answer:</u>

Velocity of rock after 2 seconds = 6.56 m/s

<u>Explanation:</u>

We have equation of motion , $s= ut+\frac{1}{2} at^2$ , s is the displacement, u is the initial velocity, a is the acceleration and t is the time.

Here height of rock in meters, h = $14t-1.86t^2$

Comparing both the equations

We will get initial velocity = 14 m/s(already given) and $\frac{1}{2} a = -1.86$

So, Acceleration, a = -3.72 $m/s^2$

Now we have equation of motion, v = u + at, where v is the final velocity, u is the initial velocity, a is the acceleration and t is the time taken.

When time is 2 seconds we need to find final velocity.

v = 14 - 3.72 * 2 = 6.56 m/s.

So, Velocity of rock after 2 seconds = 6.56 m/s

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