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4 years ago

A motion map for a motorcycle is shown. After how many seconds does the motorcycle have positive acceleration?

Physics

1 answer:

Ilya [14]4 years ago

7 0

Answer: option D. 4

Reasoning:

Assuming that the time elapsed between any two consecutive dots is the same, and that the second dot marks second 1, the column with 3 dots marks second 2, and the dot right most marks second 3, the motorcycle has positive acceleration after 4 seconds.

That is because:

1) from the first dot to the second dot: the velocity the lenght of the arrow that models the velocity decrases, which means that the acceleration is negative.

2) In the nex group of dots the length of the arrow remains equal, which means that the velocity is constant and the acceleration is 0.

3) For the last dot, the length of the arrow is greater, which means that the velocity increases, and so the acceleration is positive.

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Lerok [7]

Answer:

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3 years ago

How is a conducter different from an insulater

Maru [420]

Answer:

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3 years ago

Read 2 more answers

The best rebounders in basketball have a vertical leap (that is, the vertical movement of a fixed point on their body) of about

nadya68 [22]

Answer:

a) 4.45 m/s

b) 0.9 seconds

Explanation:

t = Time taken

u = Initial velocity

v = Final velocity

s = Displacement

a = Acceleration due to gravity = 9.81 m/s²

$v^2-u^2=2as\\\Rightarrow -u^2=2as-v^2\\\Rightarrow u=\sqrt{v^2-2as}\\\Rightarrow u=\sqrt{0^2-2\times -9.81\times 1}\\\Rightarrow u=4.45\ m/s$

a) The vertical speed when the player leaves the ground is 4.45 m/s

$v=u+at\\\Rightarrow t=\frac{v-u}{a}\\\Rightarrow t=\frac{0-4.45}{-9.81}\\\Rightarrow t=0.45\ s$

Time taken to reach the maximum height is 0.45 seconds

$s=ut+\frac{1}{2}at^2\\\Rightarrow 1=0t+\frac{1}{2}\times 9.81\times t^2\\\Rightarrow t=\sqrt{\frac{1\times 2}{9.81}}\\\Rightarrow t=0.45\ s$

Time taken to reach the ground from the maximum height is 0.45 seconds

b) Time the player stayed in the air is 0.45+0.45 = 0.9 seconds

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3 years ago

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Digiron [165]

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3 years ago

Part a consider a bird that flies at an average speed of 10.7 m/s and releases energy from its body fat reserves at an average r

Alex787 [66]

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4 years ago