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
Studentka2010 [4]
3 years ago
8

A 30 kg girl and a 25 kg boy face each other on friction-free roller skates. The girl pushes the boy, who moves away at a speed

of 1.0 m/s. What is the girl's speed?
Physics
1 answer:
Dovator [93]3 years ago
3 0

Answer: 4m/s

Explanation:

Mass of girl = m1 = 30kg

Mass of boy = m2 = 25kg

Resultant speed after collision = 1.0m/s

Speed of girl = v1

Speed of boy = v2

Momentum = mass × velocity

m1v1 - m2v2 = mv

30v1 - 25v2 = 1×m

30v1 - 25v2 = m

v1 = (m + 25v2)/30 ...eqn 1

but m1 - m2 = m

m = 30 - 25 = 5kg

v1 = (5 + 25v2)/30 ...eqn 2

v1-v2 = 1m/s

v2 = (v1 - 1)m/s

Substitute for v2 in eqn 2

v1 = [5 + 25(v1 - 1)]/30

30v1 = 5 + 25v1 - 25

30v1 - 25v1 = -20

5v1 = -20

v1 = -4m/s

Because she moved in an opposite direction to the boy, the negative sign is featured on her speed

You might be interested in
How can an individual benefit from participating in the recommended amount of physical activity?
Orlov [11]
It will help them stay in better shape resulting in better health, being more physically active, and staying happier as a result.
3 0
4 years ago
A 9 cm tall object is placed 16 cm from a converging lens forming an image at 13 cm. What is the height of the image?
Tresset [83]
The way I actually did that it was just like a little bit of a panic attack and I was like literally dying laughing at my chrome book mark and I was like literally dying laughing at the park I was laughing so loud and I’m literally gonna laughing so I can’t do tell him what he says I don’t think I
3 0
3 years ago
What will happen when a light bulb is removed from the circuit below, leaving a gap?
Charra [1.4K]

Answer:

The remaining light bulbs will go out.

Explanation:

The light bulb that was taken out routed power to the other light bulbs, there for, not giving power to the next light bulbs will make them turn off or, "go out". This may be incorrect, as you did not provide a picture of the circuit.

7 0
3 years ago
Read 2 more answers
Explain the phenomenon of polarization when a dielectric slab is subjected to an electric<br> field?
Oxana [17]

A dielectric, insulating material, or an extremely bad conductor of electrical current. Due to the absence of loosely bound, or free, electrons that could wander through the material, unlike metals, dielectrics practically do not conduct current when exposed to an electric field. Electric polarization takes place instead.

<h3>What is an Electric field?</h3>
  • An electric field is an electrical property associated with every point in the space of any form of charge. An electric field is also described as the electric force per unit charge.
  • Variable magnetic fields or electric charges are frequently the cause of electric fields. Volts per meter, a unit used in the SI, express electric field strength.
  • The force acting on the positive charge is assumed to be exerted in the direction of the field. The electric field is directed radially inwards toward the negative point charge and radially outwards from the positive charge.
  • Electric charge or magnetic fields with variable amplitudes can produce an electric field. The attraction forces that keep together atomic nuclei and electrons at the atomic scale are brought on by the electric field.

The phenomenon of polarization when a dielectric slab is subjected to an electric field:

A dielectric, insulating material, or an extremely bad conductor of electrical current. Due to the absence of loosely bound, or free, electrons that could wander through the material, unlike metals, dielectrics practically do not conduct current when exposed to an electric field. Electric polarization takes place instead.

To learn more about the electric field, refer to:

brainly.com/question/14372859

#SPJ9

8 0
2 years ago
an Olympic runner leaps over a hurdle.if the runner initial vertical speed is 2.2m/s how much will the runners center of mass be
Snowcat [4.5K]
Supposing the runner is condensed to a point and moves upward at 2.2 m/s.
It takes a time = 2.2/g = 2.2/9.8 = 0.22 seconds to increase to max height. 
Now looking at this condition in opposite - that is the runner is at max height and drops back to earth in 0.22 s (symmetry of this kind of motion). 
From what height does any object take 0.22 s to fall to earth (supposing there is no air friction)? 
d = 1/2gt²= (0.5)(9.8)(0.22)²= 0.24 m
7 0
3 years ago
Other questions:
  • Melting wax
    14·2 answers
  • Fossils cannot be used to explain changes in the earth. True or false
    6·2 answers
  • Please help!!! These questions are about specific heat capacity.
    13·1 answer
  • Diesel engines burn as much as 30% less fuel than gasoline engines of comparable size, as well as emitting far less carbon dioxi
    5·1 answer
  • Find the location of the center of mass of the earth-moon system relative to the center of earth.
    9·1 answer
  • A driver starts is parked car and within 5 seconds reaches a speed of 60km/h, as he travels east. What his acceleration?
    6·1 answer
  • Objects with masses of 155 kg and a 455 kg are separated by 0.300 m. (a) Find the net gravitational force exerted by these objec
    5·1 answer
  • The topic is finding volume. help on number 2?
    8·1 answer
  • .Ryan boiled a liter of water and then stirred sugar into it, adding more sugar until no more would dissolve in the water, creat
    14·1 answer
  • Hazel recently read an article that claimed that radio waves can cause electron displacement. Based on
    5·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!