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3 years ago

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A 30 kg child rides a 20 kg bicycle. Together, the child and the bicycle have a momentum of 110 kg-m/s. What is the velocity of

the boy and the bicycle?

1 answer:

love history [14]3 years ago

8 0

Answer:

The velocity of the boy and the bicycle is 2.2 m/s.

Explanation:

We have,

Mass of child is 30 kg and the mass of bicycle is 20 kg. The combined momentum of the child and the bicycle is 110 kg-m/s.

It is required to find the velocity of the boy and the bicycle. The momentum of an object is given in terms of mass and its velocity. So,

$p=Mv$

M is combined mass of child and bicycle

$v=\dfrac{p}{M}\\\\v=\dfrac{110}{30+20}\\\\v=2.2\ m/s$

So, the velocity of the boy and the bicycle is 2.2 m/s.

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Projectiles that strike objects are good examples of inelastic collisions. A 0.1 kg nail driven by a gas powered nail driver col

Ratling [72]

In an inelastic collision, only momentum is conserved, while energy is not conserved.

1) Velocity of the nail and the block after the collision
This can be found by using the total momentum after the collisions:
$p_f=(m+M)v_f=4.8 kg m/s$
where
m=0.1 kg is the mass of the nail
M=10 kg is the mass of the block of wood
Rearranging the formula, we find $v_f$ , the velocity of the nail and the block after the collision:
$v_f= \frac{p_f}{m+M}= \frac{4.8 kg m/s}{0.1 kg+10 kg}= 0.48 m/s$

2) The velocity of the nail before the collision can be found by using the conservation of momentum. In fact, the total momentum before the collision is given only by the nail (since the block is at rest), and it must be equal to the total momentum after the collision:
$p_i = mv_i = p_f$
Rearranging the formula, we can find $v_i$ , the velocity of the nail before the collision:
$v_i = \frac{p_f}{m}= \frac{4.8 kg m/s}{0.1 kg}=48 m/s$

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3 years ago

Read 2 more answers

A beam oflight is reflected off a mirror. If the angle of incidence is 30 degrees, according to the Law of Reflection the angle

zaharov [31]

Answer:

30°

Explanation:

According to the second law of reflection, it States that the angle of incidence i is equal to the angle of reflection r.

The angle of incidence is known to be the angle between the incident ray and the normal.

The Angle of reflection is the angle between the reflected ray and the normal.

This normal ray is a ray that is perpendicular to the surface.

According to the question, if the beam of light is reflected off the surface and its angle of incidence is 30°, its angle of reflection will also be 30° i.e i=r = 30°

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3 years ago

A dolphin in an aquatic show jumps straight up out of the water at a velocity of 13.0 m/s.

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Answer:

a) Knowns, initial speed $v_{i}=13.0 m/s$ , final speed $v_{f}=0 m/s$ and gravity due it is a constant $g=9.8m/s^{2}$

b) The maximum high reached by the dolphin is $y_{max}=8.62 m$

c) Total time is $t=2.65s$

Explanation:

a) First of all the initial speed is given at the start of the problem, gravity is constant and final speed is known any object thrown straight up reaches its max high at $0m/s$ speed.

b) Second, now that we know final speed we use $v_{f} =v_{i}-gt$ , as we clear for $t=\frac{v_{i}-v_{f} }{g}=\frac{20.0m/s}{9.8m/s^{2} }=1.32 s$ .

Then we use $y=v_{i}t-\frac{1}{2} gt^{2}=(20.0m/s)(1.32s)-\frac{1}{2} (9.8m/s^{2} ) (1.32s)^{2} =8.62m$

c)Third, finally we can use $y=v_{i}t-\frac{1}{2} gt^{2}$ , as we know $y=0m$ when the dolphin fall into the water again and $v_{i} =13.0m/s$ , then we have $0=(13m/s)t-\frac{1}{2} (9.8m/s^{2} )t^{2}$ is a quadratic form $0=t(13.0-4.9t)$ so we have $t_{i}=0s$ and $t_{f}=\frac{13}{4.90} =2.65s$

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3 years ago

Explain how birds, bats, insects, airplanes, rockets, and hot air balloons achieve their flight.

Oksi-84 [34.3K]

The birds, bats, insects, airplanes, rockets, and hot air balloons achieve their flight by creating high pressure below the aircraft and low pressure above it

<h3>What are living and non-living things?</h3>

They both consist of fundamentally simple building blocks. They are composed of substances or mass. Atmospheric and molecular building blocks make up the world.

In order to create high pressure below the aircraft and low pressure above it, airplanes employ specially built wings.

The wing receives sufficient airflow past it to counteract the weight and drag of the aircraft by utilizing a device to provide thrust, such as a propeller.

High pressure underneath the aircraft and low pressure above it is produced by specially constructed wings used by airplanes.

The wing receives enough airflow through it by the use of a thrust-generating device, like a propeller, to overcome the weight and drag of the aircraft.

The differences between how living and non-living things fly;

1. Moving both living and non-living objects consumes energy. Flying animals utilize their wings to create both lift and propulsion by moving them in relation to the body.

In contrast to most air vehicles, where the components that generate lift, wings, and thrust engines or propellers are distinct, the wings stay stationary.

Animal aviators like birds as well as natural parachuters like patagial as well as human inventions like aircraft as well as rockets that can power spacecraft and spaceplanes are just a few examples of the many things that can fly.

Hence, birds, bats, insects, airplanes, rockets, and hot air balloons achieve their flight by creating high pressure below the aircraft and low pressure above it

To learn more about living and nonliving things, refer to brainly.com/question/7807759

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1 year ago

a ship travels a port p and travels 30 km due north. then it changes course and travels 20 km in a direction 30° east of north

liq [111]

When we represent what is given to us on a coordinate plane, we have a figure as shown in the attachment.

To find the distance between P and R, we have to find the Net Displacement of the ship (brown arrow in the figure).

For that, we use the rules for Vector addition.

We see that the first displacement $D_{1}$ = 30 km (blue arrow) is along the y-axis, but the second part of the ship's journey $D_{2}$ = 20 km (red arrow) is at an angle with reference to y-axis.

So, we first find the components of the red arrow along X and Y.

Component of $D_{2}$ along X-axis is given by $D_{2x} = D_{2} Sin 30$ = 10 km

Component of $D_{2}$ along Y-axis is given by $D_{2y} = D_{2} Cos 30$ = 17.32 km

We now add all the vectors along X and along Y separately.

Net Displacement along X $D_{netX} = 10 km$

Net Displacement along Y $D_{netY} = 30 + 17.32$ = 47.32 km

Now that we have the components of the net displacement along X and Y, we make use of Pythagorean Theorem to calculate the $D_{net}$

$D_{net} = \sqrt{D_{netX} ^{2} + D_{netY} ^{2}}$

Therefore, [tex]D_{net} = 48.37 km.

Hence, the distance between the ports P and R is 48 km.

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3 years ago