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
________ In many cartoon shows, a character runs off a cliff, realizes his predicament, and lets out a scream. He continues to s
IrinaVladis [17]

Answer:

Here the source is moving away from the observer so frequency will be smaller than the actual frequency and since the speed is increasing so the frequency is decreasing with time so correct answer is

D) lower than the original pitch and decreasing as he falls.

Explanation:

As we know by the Doppler's effect of sound we have

so we will have

f = f_o(\frac{v}{v + v_s})

so here when source moves away from the observer with a some speed then the frequency of the sound observed by the observer is smaller than the actual frequency

Here we know that the speed of the source is increasing with time as the source is falling under gravity

So we can say that the pitch of the sound will decrease with time

4 0
3 years ago
What is the purpose of a branch circuit in your home?
leva [86]

Answer:

A branch circuit is the circuit conductor between the final overcurrent device protecting the circuit and the outlet(s). Branch circuits are divided into four categories: appliance, general purpose, individual and multiwire

Explanation:

7 0
3 years ago
Read 2 more answers
When an airplane flies from Dallas - Ft. Worth International airport to Los Angeles International airport, the time in the air i
Elanso [62]

Answer:

7.99 or 8 depends where you round.

Explanation:

Distance divided by time so 1246/156=7.98717948718

7 0
3 years ago
What is the average speed of a kangaroo that hops 60 m in 5 s ?
jok3333 [9.3K]
The formula for average speed is
v_{avg}= \frac{total distance}{total time}
So we can just substitute our data.
v_{avg}= \frac{60}{5}=12 \frac{m}{s} - its the result
6 0
3 years ago
Read 2 more answers
The form of energy given off by the vibrating strings of the violin is? A. Electrical Energy B. Potential Energy C. Radiant Ener
S_A_V [24]

Answer:

D . Sound energy

Explanation:

When the strings of a violin vibrate it produces sound which is sound energy. Due to the vibration of the strings the air present near the strings also vibrate in resonance with the strings. This compreesion and decompression's produced in the air is nothing but the sound. So the form of energy given off by the vibrating strings of the violin is Sound energy.

6 0
3 years ago
Other questions:
  • A proton is moving toward a stationary charged particle. Which statement correctly describes an energy change that could occur a
    7·2 answers
  • How many layers of smooth muscle help with churning food in the stomach? a. one b. two c. three d. four
    7·2 answers
  • What is the pressure of a 300 lb. object on a 100 sq. in. area?
    11·1 answer
  • What is the scientific method​
    12·2 answers
  • 70.5
    11·1 answer
  • A research vessel is mapping the bottom of the ocean using sonar. It emits a short sound pulse called "ping" downward. The frequ
    11·1 answer
  • In a 120-volt circuit having a resistance of 12 ohms, the power W in watts when a current I is flowing through is given by W=120
    7·1 answer
  • Lucy took 3 hours to cover 2/3 of a journey. She covered the
    5·1 answer
  • A 9.0 m long uniform rod with a weight of 8 N has 3 masses hanging from it; a 4N mass 1 meter from the left end, a 2 N mass 6 me
    8·1 answer
  • At baseball practice, Mason and Alfredo both picked up the same bat and neither would let go until one of them had it for himsel
    5·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!