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
BartSMP [9]
3 years ago
11

A boy on a 1.9 kg skateboard initially at rest tosses a(n) 7.8 kg jug of water in the forward direction. if the jug has a speed

of 3.2 m/s relative to the ground and the boy and skateboard move in the opposite direction at 0.65 m/s, find the boy's mass. answer in units of kg.
Physics
1 answer:
Tresset [83]3 years ago
4 0
For this case we first think that the skateboard and the child are one body.
 We have then:
 1 = jug
 2 = skateboard + boy
 By conservation of the linear amount of movement:
 M1V1i + M2V2i = M1V1f + M2V2f
 Initial rest:
 v1i = v2i = 0
 0 = M1V1f + M2V2f
 Substituting values
 0 = (7.8) (3.2) + (M2) (- 0.65)
 0 = 24.96 + M2 (-0.65)
 -24.96 = (-0.65) M2
 M2 = (-24.96) / (- 0.65) = 38.4 kg
 Then, the child's mass is:
 M2 = Mskateboard + Mb
 Clearing:
 Mb = M2-Mskateboard
 Mb = 38.4 - 1.9
 Mb = 36.5 Kg
 answer:
 the boy's mass is 36.5 Kg
You might be interested in
How do you calculate the net force when there are multiple forces in different directions?​
Artyom0805 [142]

To find F_{net} we need to use vector addition and use the x and y components. First we subtract vector 2 from vector 5 which results in a vector with a  length of 3 pointing directly east, then we use the distance formula to find the length of the net force F_{net} = \sqrt{(3)^2+(4)^2} \\  which gives F_{net} = 5. We now have a magnitude but we also need a direction, since vector 4 and vector 5 are perpendicular. Using \theta = \tan^{-1} (\frac{4}{3})   where tan^-1(y/x) we get an angle of 53 degrees. The resultant force vector is 5 distance with an angle of 53 degrees north east.

4 0
3 years ago
•Would a moving fan have energy? Why or why not.
Pepsi [2]
Moving fan has rotational kinetic energy
Non moving fan has no energy since it is in rest
7 0
3 years ago
HELPPP PLS BESTIES A pattern of stars that has been named is called a constellation. One winter evening, Jason found the star ca
Damm [24]

Answer:

D) Since the stars would move from East to West just as the Sun and Moon do.

5 0
3 years ago
A car changes speed from 25 m/s to 10 m/s in 240 seconds. Describe its acceleration.​
Dmitry_Shevchenko [17]

Explanation:

Acceleration is change in velocity over change in time:

a = Δv / Δt

a = (10 m/s - 25 m/s) / (240 s - 0 s)

a = -0.0625 m/s²

So the car decelerates at 0.0625 m/s².

7 0
3 years ago
Compare and contrast repetition and replication in a science investigation
Bas_tet [7]
Repetition occurs when multiple sets of measurements are made during one scientific investigation. Replication occurs when a scientific investigation is <span>reproduced by another person.

Thank you for posting your question here at brainly. I hope the answer will help you. Feel free to ask more questions.
</span>
3 0
3 years ago
Other questions:
  • Jefferson's administration was the beginning of popular government in the United States.
    13·1 answer
  • If the distance between two positive point charges is tripled, then the strength of the electrostatic repulsion between them wil
    14·1 answer
  • How do I solve for time if I have initial velocity and final speed?
    7·1 answer
  • Two cars are facing each other from opposite ends of a 500m long road. Car A begins travelling at a constant speed of 20m/s. At
    11·1 answer
  • A submarine dives to a depth of 100-m beneath the surface of the Pacific Ocean. The density of sea water is 1030 kg/m3. The subm
    13·1 answer
  • In what way is a piano an example of a quantized system?
    12·1 answer
  • A car starts from rest and goes due east reaching a speed of 40 m/s What additional information is needed in order to calculate
    14·1 answer
  • Describe the difference between a transverse wave and longitudinal wave. Include the parts that you would find on a transverse w
    8·2 answers
  • An alumium rod when measured with a steel scale both being at 25 degree celcius appears to be 1 meter long. If the scale is corr
    12·2 answers
  • Which object has the most thermal energy?
    7·2 answers
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!