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Rus_ich [418]
3 years ago
15

a body traveled a distance 2m in 2s and 2.2m in the next 2s. what will be the velocity at the end of the Start ​

Physics
1 answer:
Nitella [24]3 years ago
4 0

The velocity at the end of the 7th second is 1.198 m/s

Explanation:

Assuming that the motion of the body is a uniformly accelerated motion (=constant acceleration), we can use the following suvat equation:

s=ut+\frac{1}{2}at^2

where

s is the displacement

u is the initial velocity

t is the time elapsed

a is the acceleration

In the first 2 seconds, the body travels 2 m, so we have:

s_1 = 2 m\\t_1 = 2 s

So the equation can be written as

s_1=ut_1 + \frac{1}{2}at_1^2\\2=2u+2a

If we then consider the whole first 4 seconds of motion, we have:

s_2 = 2 + 2.2 = 4.2 m\\t_2 = 2+2 = 4 s

So the equation can be written as

s_2=ut_2+\frac{1}{2}at_2^2\\4.2 = 4u+8a

So we have a system of 2 equations in 2 variables:

2=2u+2a\\4.2=4u+8a

By multiplying the 1st equation by 2 and subtracting eq.(1) from eq.(2), we get

0.2=6a\\ \rightarrow a=\frac{0.2}{6}=0.033 m/s^2

And susbtituting into the 1st equation, we get

u=1-a=0.967 m/s

Now we can apply the following suvat equation:

v=u+at

And substituting t = 7 s, we find the velocity at the end of the 7th second:

v=0.967+(0.033)(7)=1.198 m/s

Learn more about accelerated motion:

brainly.com/question/9527152

brainly.com/question/11181826

brainly.com/question/2506873

brainly.com/question/2562700

#LearnwithBrainly

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A student on a skateboard is moving at a speed of 1.40 m/s at the start of a 2.15 m high and 12.4 m long incline. The total mass
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Answer:

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Explanation:

In order to calculate the work done by the student, you take into account that the total work is equal to the change of the kinetic energy of the student, as follow:

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The work done by the friction force is negative because it is against the motion of the student.

W: work done by the student = ?

Wf: work done by the friction force

Wg: work done by the gravitational force

Ff: total friction force = 41.0N

m: mass of the skateboard = 53.0kg

d: distance traveled by the student

v: final speed of the student = 6.90m/s

vo: initial speed of the student = 1.40m/s

α: angle of the incline

You first calculate the distance d, with the Pythagoras' theorem

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Furthermore, the angle α is:

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Then, you solve the equation (1) for W and replace the values of all parameters:

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The work done by the student is 609.97J

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