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2 years ago

The earth's radius is 6.37×106m; it rotates once every 24 hours.

Physics

1 answer:

Andrei [34K]2 years ago

5 0

Answer:

Speed of the point = 1.541 × 10⁶ m/h = 428 m/s

Explanation:

Modelling the earth as a sphere,

The equator and the pole have a length of an arc that's fully 90° of the whole 360° circular circumference.

A point located 1/4 of the length of the arc between the equator and the pole has an angle (1/4) × 90° arc = 22.5°.

On the attached image, θ = 22.5°, so Φ = 90° - 22.5° = 67.5°

To obtain the radius of the point on the globe

From the image again, it shows that trigonometric relations can be used to obtain this radius

Sin Φ = (radius of the point)/(radius of the earth)

Sin 67.5 = radius of the point/(6.37 × 10⁶)

Radius of the point = 6.37 × 10⁶ × 0.9239 = 5.885 × 10⁶ m

Speed of the point on the globe = (circumference of the circular path mapped out by the point during rotation)/(24 hours)

circumference of the circular path mapped out by the point during rotation = 2πr = 2π × 5.885 × 10⁶ = 3.6977 × 10⁷ m

Speed of the point = 3.6977 × 10⁷/24 = 1.541 × 10⁶ m/h = 428 m/s

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What is the weight of an object (mass = 60 kilograms) on Mars, where the acceleration due to gravity is 3.75 meters/second2?. Se

Shalnov [3]

Weight = mass * gravity = 60 kg * 3.75 m/s² = 225 N

Option D.

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3 years ago

a car moving at 11 m/s crashes into an obstacle and stops in 0.26s. compute the Force that a seatbelt exerts on a 21-kg child to

Natalka [10]

Answer:

890 N

Explanation:

Acceleration is change in velocity over change in time.

a = Δv / Δt

a = (11 m/s − 0 m/s) / 0.26 s

a = 42.3 m/s²

Force is mass times acceleration.

F = ma

F = (21 kg) (42.3 m/s²)

F ≈ 890 N

4 0

3 years ago

An object has 1200 J of gravitational potential energy when it is dropped. Right when the object hits the ground how much kineti

Fittoniya [83]

Answer:

The kinetic energy is 1200 J

Explanation:

The Principle of Conservation of energy states that "energy is neither created nor destroyed, it is transformed".

This means that energy can be transformed from one form to another, but the total amount of energy always remains constant, that is, the total energy is the same before and after each transformation.

The mechanical energy of a body or a physical system is the sum of its kinetic energy and the potential energy. According to the Principle of Conservation of Energy for mechanical energy, the total mechanical energy that a body possesses is constant at every instant of time.

Since mechanical energy is equal to the sum of kinetic energy and gravitational potential energy that a body possesses, the only way to stay constant is that:

when the kinetic energy increases the gravitational potential energy decreases,
when gravitational potential energy increases, kinetic energy decreases.

Due to the Principle of Conservation of Energy you can say that the gravitational potential energy is converted to kinetic energy. So Gravitational potential energy at the top = kinetic energy at the bottom

The kinetic energy is 1200 J

5 0

2 years ago

By means of a rope whose mass is negligible, two blocks are suspended over a pulley, as the drawing shows, with m1 = 12.1 kg and

puteri [66]

Answer:

14.8 kg

Explanation:

We are given that

$m_1=43.7 kg$

$m_2=12.1 kg$

$g=9.8 m/s^2$

$a=\frac{1}{2}(9.8)=4.9 m/s^2$

We have to find the mass of the pulley.

According to question

$T_2-m_2 g=m_2 a$

$T_2=m_2a+m_2g=m_2(a+g)=12.1(9.8+4.9)=177.87 N$

$T_1=m_1(g-a)=43.7(9.8-4.9)=214.13 N$

Moment of inertia of pulley= $I=\frac{1}{2}Mr^2$

$(T_2-T_1)r=I(-\alpha)=\frac{1}{2}Mr^2(\frac{-a}{r})=\frac{1}{2}Mr(-4.9)$

Where $\alpha=\frac{a}{r}$

$(177.87-214.13)=-\frac{1}{2}(4.9)M$

$-36.26=-\frac{1}{2}(4.9)M$

$M=\frac{36.26\times 2}{4.9}=14.8 kg$

Hence, the mass of the pulley=14.8 kg

6 0

2 years ago

When a force of 20.0N is applied to a spring, it elongates 0.20m. Determine the period of oscillation of a 4.0kg object suspende

choli [55]

So what we can do is apply the Hooke's law wich states that
F = -kx ( P.S the -ve sign means opposite in direction )
Also we will need to determine the spring's constant with the formula:
k = F / x
Where F = the force ( = 20 N )
x = the displacement of the end of the spring from it's position ( = 0.20 m )
k = the spring's constant ( = unknown )
So this would be: k = 20 / 0.20 = 100 N/m
The period of oscillation of 4 kg : T = 2 * pi * square root m / k
T = 2 * pi * square root 4 / 100
T = 1.256 seconds
Hope it helps

7 0

2 years ago