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3 years ago

8

A ball is dropped from a 100-m tall building. Neglecting air resistance, what will the speed of the ball be when it reaches the

ground 4.5 seconds later?

1 answer:

VARVARA [1.3K]3 years ago

5 0

V=u+at=0+(9.8)(4.5)=44.1

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In complete sentences describe the energy flow between the Sun, the Earth, and space

agasfer [191]

Answer: The energy from the sun passes through space in the form of invisible waves to the earth surface. It heats up the earth’s surface causing variation in climate.
Explanation:
The amount of incoming energy from the Sun decides the weather and climate of earth. If the energy that is incoming and outgoing on the earth, then climate is in equilibrium. The balance is depending on the scattering, absorption, reflection and transformation of energy.
The energy from sun passes through space and reaches the earth’s surface. On reaching surface, the solar energy warms the atmosphere releasing heat energy which gets transferred throughout the planets system by radiation, conduction and convection. Conduction happens in the atmosphere within first several millimeters close to the surface. This heated air expands as it is dense and rises causing transfer of heat to atmosphere through convection process. It results in formation of clouds.
The radiant energy from sun is transmitted via space in form of invisible waves. But much of the suns radiant energy, is transmitted back to atmosphere. The objects on earth like land, plants, animals absorb radiant energy as heat of which one third gets re-radiated back to atmosphere that is absorbed by carbon dioxide and water vapor. The atmosphere radiates heat energy back to earth increasing the earth temperature. This trapping of radiation is greenhouse effect.
The thermal energy obtained by convection currents are responsible for wind, cloud formation, and weather formation. The hydrosphere that comprises of 70% of earth’s surface absorbs solar energy.
On the basis of the above explanation is:
The energy from the sun passes through space in the form of invisible waves to the earth surface. It heats up the earth’s surface causing variation in climate.

6 0

3 years ago

A ball is thrown horizontally from the top of a building 37.5 m high. The ball strikes the ground at a point 80.3 m from the bas

trasher [3.6K]

Answer:

t = 2.77 s

Explanation:

The ball in its movement describes a curved line called a semiparabola, therefore two coordinates are required to fix the position at each instant of time, since the movement is performed in the X-Y plane:

Equation of movement of the ball in the X axis

X = v₀x*t Equation (1)

Equation of movement of the ball in the Y axis

Y = y₀+ v₀y*t -½ g*t² Equation (2)

Where

X : horizontal position in meters (m)

Y : vertical position in meters (m)

y₀ : initial vertical position in meters (m)

v₀x : X-initial speed in m/s

v₀y : Y-initial speed in m/s

g: acceleration due to gravity in m/s²

t : time to position (X,Y)

Data

y₀ = 37.5 m

v₀y = 0

g = 9.8 m/s²

Problem development

The time the ball remains in the air is the same as the ball takes to touch the floor, that is, Y = 0

We apply the Equation (2):

Y = y₀+ (v₀y)*t - (½) g*t²

0 = 37.5 +(0)*t- (1/2)*(g)*t²

0 = 37.5 - (1/2)*(9.8)*t²

(1/2)*(9.8)*t² = 37.5

t² = (2)(37.5)/(9.8)

$t= \sqrt{\frac{2*37.5}{9.8} }$

t = 2.77 s

5 0

3 years ago

In which layer of the sun is energy transfferred between atoms?

sasho [114]

Answer:

Core is the layer of the sun is energy transferred between atoms.

Explanation:

4 0

3 years ago

The switch has been open for a long time before it is closed at t = 0. what is ustored, the total stored energy in the circuit e

Ivahew [28]

0. No time comparison.

5 0

3 years ago

While sitting in a swivel chair, you push against the floor with your heel to make the chair spin. The 6.7 N frictional force is

nexus9112 [7]

Answer:

I = 1.4kgm²

Explanation:

The rotational motion is caused by the frictional force, which generates a torque on the system. As there is no other force that creates a torque, this can be expressed in the equation of rotational motion below:

$\tau_f =I\alpha\\\\$

And $\tau_f=rf$ , where r is the distance from the point of application and the rotation axis, and f is the magnitude of the frictional force. This is because the frictional force is applied in the direction that causes the greatest angular acceleration (this is, 90°) and $rf\sin90\°=rf$ . Then, we have that:

$rf=I\alpha\\\\\implies I=\frac{rf}{\alpha}\\\\$

Plugging in the given values, we obtain:

$I=\frac{(0.39m)(6.7N)}{1.8rad/s^{2} } =1.4kgm^{2}$

In words, the total moment of inertia is equal to 1.4kgm².

6 0

3 years ago