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
olga55 [171]
2 years ago
9

On an ice skating rink, a girl of mass 50 kg stands stationary, face to face with a boy of mass 80 kg. The children push off of

one another, and the boy moves away with a velocity of 3 m/s. What is the final velocity of the girl? â€"1. 9 m/s 1. 9 m/s â€"4. 8 m/s 4. 8 m/s.
Physics
1 answer:
sasho [114]2 years ago
5 0

The velocity of the girl is  -4.8 m/s.

Using the principle of conservation of linear momentum, The total momentum of  bodies before and after collision is constant. Since the two objects are stationary, the initial momentum of each body is zero.

Thus;

0 = (80 × 3) + (50 × v)

0 = 240 + 50 v

-240 = 50 v

v = -240/50

v = -4.8 m/s

Note that the negative sign shows that the velocity of the girl is in opposite direction that that of the girl.

Learn more about momentum: brainly.com/question/904448

You might be interested in
100 POINTS FOR CORRECT ANSWER/EXPLANATION
Shalnov [3]

Answer:

6 N

Explanation:

Let's start with the small block m on top.  There are four forces:

Weight force mg pulling down, normal force N₁ pushing up, tension force T pulling right, and friction force N₁μ pushing left (opposing the direction of motion).

Now let's look at the large block M on bottom.  There are seven forces:

Normal force N₁ pushing down (opposite and equal from block m),

Friction force N₁μ pushing right (opposite and equal from block m),

Weight force Mg pulling down,

Tension force T pulling right,

Applied force F pulling left,

Normal force N₂ pushing up,

and friction force N₂μ pushing right (opposing the direction of motion).

So you've correctly identified the free body diagrams.

Now apply Newton's second law.  Sum of forces in the y direction for block m:

∑F = ma

N₁ − mg = 0

N₁ = mg

Sum of forces in the x direction:

∑F = ma

T − N₁μ = 0

T = N₁μ

T = mgμ

Sum of forces in the y direction for block M:

∑F = ma

-N₁ − Mg + N₂ = 0

N₂ = N₁ + Mg

N₂ = mg + Mg

Sum of forces in the x direction:

∑F = ma

N₁μ + T − F + N₂μ = 0

F = N₁μ + T + N₂μ

F = mgμ + mgμ + (mg + Mg)μ

F = gμ(3m + M)

Since M = 2m:

F = 5gμm

Plug in values:

F = 5 (10 m/s²) (0.400) (0.300 kg)

F = 6 N

8 0
3 years ago
Read 2 more answers
When a pitcher throws a softball to a catcher, the vibration of the atoms that make up the softball is ____________ energy, whil
Molodets [167]
The vibration is thermal energy ("heat" energy which every object possesses).
The second one is kinetic energy ("motion" energy of a massive object)
5 0
3 years ago
If a battery causes a wire to carry a current of 4 Amps how many coulombs of charge flow past any point in the wire in 3 seconds
BabaBlast [244]

▪▪▪▪▪▪▪▪▪▪▪▪▪  {\huge\mathfrak{Answer}}▪▪▪▪▪▪▪▪▪▪▪▪▪▪

According to above question ~

  • Current (I) = 4 Amperes

  • Time (t) = 3 seconds

  • Charge (q) = ?

Let's find the charge (q) by using formula ~

  • I =  \dfrac{q}{t}

  • 4 =  \dfrac{q}{3}

  • q = 4 \times 3

  • q = 12 \:  \: coulombs

Hence, 12 coulombs of charge flow past any point in the wire in 3 seconds

7 0
3 years ago
A 2000 kg car slams on the brakes and slows down at a rate of -10 m/s2. How much force are the brakes applying?
Gemiola [76]

Answer:

-20,000N

Explanation:

Force (N) = mass (kg) x acceleration (m/s²)

So,

Force = 2000 x -10

= -20,000N (Newtons)

5 0
2 years ago
Suppose the coefficient of static friction between a quarter and the back wall of a rocket car is 0.330. At what minimum rate wo
Helga [31]

Answer:3.23 m/s^2

Explanation:

Given

\mu_s =0.330

Frictional Force is balanced by force due to car acceleration

Frictional force F_s

F_s=ma_{min}

\mu_sN=ma_{min}

\mu_s\cdot mg=ma_{min}

a_{min}=\mu_s \cdot g=0.330\times 9.8=3.23 m/s^2

6 0
3 years ago
Other questions:
  • Which of these is a substance or compound that kills or inhibits bacteria?
    9·1 answer
  • The force of gravity between two objects depends on ___________.
    5·1 answer
  • Specific heat capacity​
    8·1 answer
  • An astronaut throws a rock. the rock travels through outer space at a constant velocity. which statement applies to the motion o
    6·2 answers
  • Do compressional waves need a medium? If so which one would be the fastest ans slowest medium.
    11·1 answer
  • A space transportation vehicle releases a 470-kg communications satellite while in a circular orbit 350 km above the surface of
    7·1 answer
  • You hear 2 beats per second when two sound sources, both at rest, play simultaneously. The beats disappear if source 2 moves tow
    10·1 answer
  • When we add or remove energy from a substance, what kind of changes can we observe? Can they happen at the same time ?
    5·1 answer
  • What is the acceleration at 3 seconds?<br><br> Please explain your answer. Thank you :]
    12·1 answer
  • What type of matter is always made up of only one kind of atom
    15·2 answers
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!