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3 years ago

What is the student's kinetic energy at the bottom of the hill if he is moving

Physics

1 answer:

soldi70 [24.7K]3 years ago

5 0

Answer:

KE = 10530 J or 10.53 KJ

Explanation:

The formula for kinetic energy is KE = 1/2 mv^2

Let's apply the formula:

KE = 1/2 mv^2

KE = 1/2 (65kg) (18m/s)^2

KE = 10530 J or 10.53 KJ

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A car travels initially at 24 m/s, until it enters the highway. If the car accelerates at 4 m/s^2 for a 96 meters, what is the c

marishachu [46]

initial velocity=u=24m/s
Acceleration=a=4m/s^2
Distance=s=96m
Final velocity=v

Using 3rd equation of kinematics

$\boxed{\Large{\sf v^2-u^2=2as}}$

$\\ \Large\sf\longmapsto v^2=u^2+2as$

$\\ \Large\sf\longmapsto v^2=24^2+2(4)(96)$

$\\ \Large\sf\longmapsto v^2=576+768$

$\\ \Large\sf\longmapsto v^2=1344$

$\\ \Large\sf\longmapsto v=\sqrt{1344}$

$\\ \Large\sf\longmapsto v=36.6m/s$

3 0

3 years ago

A small rubber ball is launched by a compressed-air cannon from ground level with an initial speed of 11.8 m/s directly upward.

Fantom [35]

Answer:

7.09683 m

1.20285 s

2.4057 s

11.8 m/s

Explanation:

t = Time taken

u = Initial velocity

v = Final velocity

s = Displacement

a = Acceleration

g = Acceleration due to gravity = 9.81 m/s² (negative up, positive down)

From equation of motion we have

$v^2-u^2=2as\\\Rightarrow s=\frac{v^2-u^2}{2a}\\\Rightarrow s=\frac{0^2-11.8^2}{2\times -9.81}\\\Rightarrow s=7.09683\ m$

The maximum height above the ground that the ball reaches is 7.09683 m

$v=u+at\\\Rightarrow t=\frac{v-u}{a}\\\Rightarrow t=\frac{0-11.8}{-9.81}\\\Rightarrow t=1.20285\ s$

Time taken to go up is 1.20285 s it will take the same time to come down so total time taken to reach the ground after it is shot is 1.20285+1.20285 = 2.4057 s

$v=u+at\\\Rightarrow v=0+9.81\times 1.20285\\\Rightarrow v=11.8\ m/s$

The velocity just before it hits the ground is 11.8 m/s

6 0

2 years ago

A 29 foot ladder leans against a building so that the angle between the ground and the ladder is 75 ∘ . How high does the ladder

Aloiza [94]

Answer:

28.01m

Explanation:

Opp/Hyp = Sin

Sin 75 = x/29

x = 29 sin 75

x = 28.01m

3 0

2 years ago

Javier wants to improve his flexibility and increase his personal discipline. Which community resource should he select?

Dovator [93]

Karate class, kicking high and ducking fast makes you much more flexible and you must pay respects to those ou fight with and be intune with yourself to do it right, in other words karate is the answer.

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3 years ago

How are physical descriptions and physical properties similar

elena55 [62]

They are both used to observe and describe matter.

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3 years ago

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