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NemiM [27]
3 years ago
6

A person jogs eight complete laps around a quarter-mile track in a total time of 13.1 minutes

Physics
1 answer:
ExtremeBDS [4]3 years ago
5 0
Speed and velocity have the same magnitudes. The only difference is that speed is a scalar quantity and velocity is a vector quantity. In other words, speed is just a magnitude, while velocity is a magnitude with direction. They're essentially the same.

Let's convert miles to meters and minutes to seconds

1/4 mile = 402.34 meters ( 1 mile = 1609 m)
13.1 minutes = 786 seconds (1 minute = 60 seconds)

Speed is calculated as distance over time, thus,

Speed = (402.34 meters)*8/786 seconds
a.) Speed = 4.1 m./s
b.) Velocity = 4.1 m/s

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A particular uniform solid disk has a mass of 24.0 kg and a radius of 1.50 m. The disk is rotating about an axle passing through
Thepotemich [5.8K]

Answer:

L = 81 Kg.m^2/s^2

Explanation:

Angular momentum is calculated as:

L = I * ω

The inertia of the disc is:

I = 1/2 * M *R^2 = 1/2 * 24 * (1.5)^2=27Kg.m^2

So, the angular momentum is:

L = 27 Kg.m^2* 3rad/s=81Kg.m^2/s^2

6 0
4 years ago
a circus performer launches himself from a springboard with an initial velocity of 21 m/s at an angle of 75 toward a platform ha
kherson [118]

Answer:

The circus performer falls back down to the ground

Explanation:

The question parameters are;

The initial velocity of the circus performer = 21 m/s

The angle in which the performer launches himself = 75° towards the platform

The height of the platform above the ground = 20 m

The horizontal distance of the platform from the springboard = 15 m

The vertical motion of the circus performer is given by the following projectile motion relation;

y = y₀ + v₀·sinθ₀t-1/2·g·t²

Where;

y = Height reached by the circus performer

y₀ = Initial height of the the circus performer (the springboard) = 0 m

v₀ = Initial velocity of the the circus performer = 21 m/s

θ₀ = The angle with which the circus performer launches himself = 75°

t = The time of ,light of the circus performer

g = The acceleration due to gravity

Therefore, when the height is 20 m, we have;

20 = 21*sin(75)*t - 1/2*9.81*t²

Which gives;

21*sin(75)*t - 1/2*9.81*t² - 20 = 0

Factorizing using a graphing calculator, gives;

t = 1.623 or t = 2.513

Therefore, the circus performer passes the 20 m mark twice, in his motion, where the first time is when he is on his way up while the second time is when he is on his way down

The horizontal motion of the circus performer is given by the following projectile motion relation;

x = x₀ + v₀*cos(θ₀)* t

Where;

x₀ = The initial position of the circus performer in relation to the final position = 0

Plugging in the value of t when y = 20, we get;

x = 21×cos(75)×1.623 = 8.82 m, which is less than the 15 m platform distance from the spring board

Checking the other time value, we have;

x = 21×cos(75)×2.513 = 13.66 m which is also less than the 15 m platform distance from the spring board

Therefore, the circus performer misses the platform and falls back down to the ground.

8 0
3 years ago
Transfer payments are used to redistribute money to various segments of society.<br><br> T/F
jenyasd209 [6]

welp i think the answer is true

4 0
3 years ago
Read 2 more answers
The specific heat of Aluminum is 0.9 J/g K. How much heat is lost as a 100 gram sample of Aluminum is dropped into a beaker of w
otez555 [7]
Energy=mass*SHC*temp change
=100*0.9*75
=6750J
6 0
4 years ago
A listener triples his distance from a source that emits sound uniformly in all directions. by how many decibels does the sound
Novay_Z [31]
Sound intensity goes inversely as the square of the distance from the source. This is easy to understand if you think of the total sound energy spread out over the surface of a sphere with the source at the center. The surface area of the sphere goes as r^2, so the power density goes inversely as such.

The decibel change is simply

Change = 10 log10( (1/3)^2 ) = -9.54 dB
8 0
3 years ago
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