1answer.
Ask question
Login Signup
Ask question
All categories
  • English
  • Mathematics
  • Social Studies
  • Business
  • History
  • Health
  • Geography
  • Biology
  • Physics
  • Chemistry
  • Computers and Technology
  • Arts
  • World Languages
  • Spanish
  • French
  • German
  • Advanced Placement (AP)
  • SAT
  • Medicine
  • Law
  • Engineering
STatiana [176]
3 years ago
8

A 45.0-kg girl stands on a 13.0-kg wagon holding two 18.0-kg weights. She throws the weights horizontally off the back of the wa

gon at a speed of 6.5 m/s relative to herself . Assuming that the wagon was at rest initially, what is the speed of the girl relative to the ground after she throws both weights at the same time
Physics
1 answer:
topjm [15]3 years ago
4 0

Answer:

v = 4.0 m/s

Explanation:

  • Assuming no external forces acting during the instant that the girl throws the weights, total momentum must be conserved.
  • Since all the masses at rest initially, the initial momentum must be zero.
  • So, due to momentum must keep constant, final momentum must be zero too, as follows:

       p_{f} = m_{w} * v_{w} + m_{g+w} *v_{g+w} = 0 (1)

  • Assuming the direction towards the back of the wagon as positive, and replacing the masses in (1), we can solve for vg, as follows:

       v_{g+w} =- \frac{m_{w} *v_{w}}{m_{g+w} } =  - \frac{36.0kg *6.5m/s}{58.0kg } = -4.0m/s  (2)

  • This means that the girl (along with the wagon on she is standing) will move at a speed of 4.0 m/s in an opposite direction to the one she threw the weights.
You might be interested in
Flying against the wind, an airplane travels 2670 km in 3 hours. Flying with the wind, the same plane travels 11,070 km in 9 hou
xxMikexx [17]

Answer:

speed of plane in still air = 1060 km/h

speed of wind = 170 km/h

Explanation:

Let teh speed of plane in still air is vp and the speed of air is va.

Irt travels 2670 km in 3 hours against the wind

So,

vp - va = 2670 / 3 = 890 km/h ..... (1)

It travels 11070 km in 9 hours along the wind.

vp + va = 11070 / 9 = 1230 km/h .... (2)

Adding both the equations

2 vp = 2120

vp = 1060 km/h

and va = 1230 - vp = 1230 - 1060 = 170 km/h

5 0
3 years ago
Choose the correct statement regarding energy production in the interior of a star and energy production in a power plant. A sta
sergij07 [2.7K]

Answer:

A star uses fusion as an energy source by building larger atoms from smaller atoms.

Explanation:

Nuclear fission and fusion are two processes at which an atomic nucleus is changed to produce energy. Fission is the process splitting heavy atomic into lighter atomic nuclei.

So, fusion is the combination of smaller atoms to form larger atoms and star uses this as source of energy.

Fusion is the process at which light atomic nuclei are merged or fused together to form heavier nuclei.

The energy source for all stars is nuclear fusion. In a nuclear fusion reaction, the nuclei of two atoms combine to create a new atom. Most commonly, in the core of a star, two hydrogen atoms fuse to become a helium atom.

8 0
3 years ago
Read 2 more answers
A student wanted to check her idea that a planet that is closer to the Sun receives more of the Sun’s energy than a planet that
goblinko [34]

Answer:

C. a clamp light with a 150-W lightbulb placed 25 cm from the radiometer

Explanation:

because the temperature has to be set, meaning it can't change, and it should be a different distance away than the first one.

Hope this helps! Stay safe!

3 0
3 years ago
Read 2 more answers
Please answer-WILL MARK THE BEST ANSWER AS BRAINLIEST (100 POINTS)
Masja [62]

Answer:

The Earth’s lithosphere, which includes the crust and upper mantle, is made up of a series of pieces, or tectonic plates, that move slowly over time.

A divergent boundary occurs when two tectonic plates move away from each other. Along these boundaries, earthquakes are common and magma (molten rock) rises from the Earth’s mantle to the surface, solidifying to create new oceanic crust. The Mid-Atlantic Ridge and Pacific Ring of Fire are two examples of divergent plate boundaries.

When two plates come together, it is known as a convergent boundary. The impact of the colliding plates can cause the edges of one or both plates to buckle up into a mountain ranges or one of the plates may bend down into a deep seafloor trench. A chain of volcanoes often forms parallel to convergent plate boundaries and powerful earthquakes are common along these boundaries.

At convergent plate boundaries, oceanic crust is often forced down into the mantle where it begins to melt. Magma rises into and through the other plate, solidifying into granite, the rock that makes up the continents. Thus, at convergent boundaries, continental crust is created and oceanic crust is destroyed.

Two plates sliding past each other forms a transform plate boundary. One of the most famous transform plate boundaries occurs at the San Andreas fault zone, which extends underwater. Natural or human-made structures that cross a transform boundary are offset—split into pieces and carried in opposite directions. Rocks that line the boundary are pulverized as the plates grind along, creating a linear fault valley or undersea canyon. Earthquakes are common along these faults. In contrast to convergent and divergent boundaries, crust is cracked and broken at transform margins, but is not created or destroyed.

5 0
2 years ago
Read 2 more answers
What type of force keeps the Earth in orbit around the Sun?
faust18 [17]
The answer is the suns gravity
5 0
3 years ago
Other questions:
  • How much work is accplished when a force of 250 n pushes a box accross the floor for a distance of 50 meters
    8·1 answer
  • What is the main difference between the atmospheres of Jupiter and Neptune?
    12·2 answers
  • Two blocks with masses 1 and 2 are connected by a massless string that passes over a massless pulley as shown. 1 has a mass of 2
    14·1 answer
  • A forklift raises a crate weighing 8.35 × 102 newtons to a height of 6.0 meters. What amount of work does the forklift do?
    12·2 answers
  • A perpetual-motion machine can never be built because it is not possible to eliminate...
    7·2 answers
  • Air enters a 16-cm-diameter pipe steadily at 200 kPa and 20°C with a velocity of 5 m/s. Air is heated as it flows, and it leaves
    15·1 answer
  • Ulesr...<br> 4.What makes the molecular shape of Co, and NH, different? (2 points)<br> luence.
    7·1 answer
  • What force (in N) must be exerted on the master cylinder of a hydraulic lift to support the weight of a 2100 kg car (a large car
    14·1 answer
  • Which of the following situations would violate the second law of
    10·1 answer
  • A car travels straight for 20 miles on a road that is 30° north of east. What is the east component of the car’s displacement
    10·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!