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2 years ago

4. How long does it take a car traveling at 45 km/h to travel 100.0 m? 4500m

Physics

1 answer:

Trava [24]2 years ago

8 0

Answer:

8.0s

Explanation:

45 km/h ÷ 3.6 = 12.5 m/s

t.v = d/t

vt/v = d/v

t = d/v = 100.0m /12.5 m/s = 8.0s

Hope this helps!!

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What items resemble the path of light when it travels through space?

777dan777 [17]

Laser light. I suppose..

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2 years ago

A basketball player throws a chall -1 kg up with an initial speed of his hand at shoulder height = 2.15 m Le gravitational poten

Talja [164]

Complete Question:

A basketball player tosses a basketball m=1kg straight up with an initial speed of v=7.5 m/s. He releases the ball at shoulder height h= 2.15m. Let gravitational potential energy be zero at ground level

a) Give the total mechanical energy of the ball E in terms of maximum height hn it reaches, the mass m, and the gravitational acceleration g.

b) What is the height, hn in meters?

Answer:

a) Energy = mghₙ

b) Height, hₙ = 5.02 m

Explanation:

a) Total energy in terms of maximum height

Let maximum height be hₙ

At maximum height, velocity, V=0

Total mechanical energy , E = mgh + 1/2 mV^2

Since V=0 at maximum height, the total energy in terms of maximum height becomes

Energy = mghₙ

b) Height, hₙ in meters

mghₙ = mgh + 1/2 mV^2

mghₙ = m(gh + 1/2 V^2)

Divide both sides by mg

hₙ = h + 0.5 (V^2)/g

h = 2.15m

g = 9.8 m/s^2

V = 7.5 m/s

hₙ = 2.15 + 0.5(7.5^2)/9.8

hₙ = 2.15 + 2.87

hₙ = 5.02 m

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2 years ago

A heat engine extracts 42. 53 kj from the hot reservior and exhausts 17. 69 kj into the cold reservior. what is the work done?

ludmilkaskok [199]

The answer is 24.84kJ.

We apply the expression for the work done by the heat engine is,

$W=E_{i n}-E_{o u t}$ . Putting all given values in the equation we get the final answer.

What is heat engine?

A heat engine is a machine that uses heat to generate power. It draws heat from a reservoir, uses that heat to produce work, such as move a piston or lift weights, and then releases that heat energy into the sink.
We are given:The heat input is $E_{i n}=42.53 \mathrm{~kJ}$ . The heat output is $E_{o u t}=17.69 \mathrm{~kJ}$ .
The expression for the work done by the heat engine is, $W=E_{i n}-E_{o u t}$
Substituting the given values in the above expression, we will get $W =42.53 \mathrm{~kJ}-17.69 \mathrm{~kJ}$ =24.84kJ.
Thus, the work done by the heat engine is 24.84kJ.

To learn more about heat engine visit: brainly.com/question/15735984

#SPJ4

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1 year ago

An apple weighs 1.00 N. When you hang it from the end of a long spring of force constant 1.50 N/m and negligible mass, it bounce

Ierofanga [76]

Answer:

2.67 m

Explanation:

k = Spring constant = 1.5 N/m

g = Acceleration due to gravity = 9.81 m/s²

l = Unstretched length

Frequency of SHM motion is given by

$f_s=\dfrac{1}{2\pi}\sqrt{\dfrac{k}{m}}$

Frequency of pendulum is given by

$f_p=\dfrac{1}{2\pi}\sqrt{\dfrac{g}{l}}$

Given in the question

$f_p=\dfrac{1}{2}f_s$

$\dfrac{1}{2\pi}\sqrt{\dfrac{g}{l}}=\dfrac{1}{2}\dfrac{1}{2\pi}\sqrt{\dfrac{k}{m}}\\\Rightarrow \sqrt{\dfrac{g}{l}}=\dfrac{1}{2}\sqrt{\dfrac{k}{m}}\\\Rightarrow \dfrac{g}{l}=\dfrac{1}{4}\dfrac{k}{m}\\\Rightarrow l=\dfrac{4gm}{k}\\\Rightarrow l=\dfrac{4\times 9.81\times \dfrac{1}{9.81}}{1.5}\\\Rightarrow l=2.67\ m$

The unstretched length of the spring is 2.67 m

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2 years ago

Is the process of changing from one phase of matter to another a physical change or a chemical change? Explain why. please asap

Andreas93 [3]

The process of changing from one phase of matter to another is a physical matter.

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2 years ago