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3 years ago

Could someone help me with these few problems

Physics

1 answer:

ivolga24 [154]3 years ago

4 0

1. Pressure = Force/Area

When a ballon is pressed against many pins then the area is increased as compared to when it is pressed against a single pin. The force by which the balloon is pressed remains the same. Less the area, more the pressure. So, the balloon pops when it is pressed against one pin.

2. The candle goes off when covered with a glass because for burning the candle need oxygen. When glass on placed on the candle then the oxygen supply is stopped. So, when available oxygen is finished, the candle goes off. Water rises in the glass, because when the candle is burning, it expands the air inside the glass due to its heat. But when candle wents off, the air is cooled again and it contracts. So, a vacuum is created. That's why the water rises in the glass to fill the vacuum and to balance the air pressure inside and outside the glass.

3. Objects tend to maintain their state of motion or rest unless subjected to an external force. This property is called Inertia. More the mass more the inertia. When sudden brakes are applied, then our body still tends to remain in motion. That's why our body go forward.

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A 50 W light bulb is plugged into a standard

wolverine [178]

Answer:

$1.26

Explanation:

Power =energy/ time

energy =powerxtime

energy =50x31x24=37200

=37.2kwh

1kwh =3.39

37.2kwh=3.39x37.2=126.108cent

=$1.26

8 0

3 years ago

A projectile is fired with an initial velocity of 120.0 meters per second at an angle, θ above the horizontal. If the projectile

k0ka [10]

Answer:

θ = 62.72°

Explanation:

The projectile describes a parabolic path:

The parabolic movement results from the composition of a uniform rectilinear motion (horizontal ) and a uniformly accelerated rectilinear motion of upward or downward motion (vertical ).

The equation of uniform rectilinear motion (horizontal ) for the x axis is :

x = x₀+ vx*t Formula (1)

vx = v₀x

Where:

x: horizontal position in meters (m)

x₀: initial horizontal position in meters (m)

t : time (s)

vx: horizontal velocity in m/s

v₀x: Initial speed in x in m/s

The equations of uniformly accelerated rectilinear motion of upward (vertical ) for the y axis are:

y= y₀+(v₀y)*t - (1/2)*g*t² Formula (2)

vfy= v₀y -gt Formula (3)

Where:

y: vertical position in meters (m)

y₀ : initial vertical position in meters (m)

t : time in seconds (s)

v₀y: initial vertical velocity in m/s

vfy: final vertical velocity in m/s

g: acceleration due to gravity in m/s²

Data

v₀ = 120 m/s , at an angle θ above the horizontal

v₀x= 55 m/s

x-y components of the initial velocity ( v₀)

v₀x = v₀*cosθ Equation (1)

v₀y = v₀*sinθ Equation (2)

Calculating of the angle θ

We replace data in the Equation (1)

55 = 120*cosθ

cosθ = 55 / 120

$\theta = cos^{-1}( \frac{55}{120} )$

θ = 62.72°

3 0

3 years ago

A girl is shown at position A on a swing when the seat is directly below the support bar. The seat is then at height A as shown

MrRa [10]

Answer:

1. The potential energy of the swing is the greatest at the position B.

2. As the swing moves from point B to point A, the kinetic energy is increasing.

Explanation:

Even though the syntax of the text is not completely clear, likely because it accompanies a drawing that is not included, it results clear that the posittion A is where the seat is at the lowest position, and the position B is upper.

The gravitational potential energy is directly proportional to the height of the objects with respect to some reference altitude. Thus, when the seat is at the position A the swing has the smallest potential energy and when the seat is at the position B the swing has the greatest potential energy.

Regarding the forms of energy, as the swing moves from point B to point A, it is going downward, gaining kinetic energy (speed) at the expense of the potential energy (losing altitude). When the seat passes by the position A, the kinetic energy is maximum and the potential energy is miminum. Then the seat starts to gain altitude again, losing the kinetic energy and gaining potential energy, up to it gets to the other end,

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3 years ago

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3 years ago

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What condition is most necessary to build a glacier?

OLga [1]

The most necessary condition to build a glacier is: More snow must fall in the winter than melts in the summer.
when More snow fall in the winter than it melts in the summer, the snow will start to accumulate on the top of the higher terrain. This accumulation will form an abundant amount of snow on higher terrain, which will fall as glacier as soon as its temperature drop.

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3 years ago