HomeworkLib
Question

A boy of mass 60 kg and a girl of mass 40 kg are together and...

A boy of mass 60 kg and a girl of mass 40 kg are together and at rest on a frozen pond and push each other apart. The girl moves in a negative direction with a speed of 3 m/s. What must be the final momentum of the boy?
science   physics   
0 0
Add a comment Improve this question Transcribed image text
Next > < Previous
Sort answers by oldest

Homework Answers

Answer #1

Given:

Mass of boy = 60 kg

Mass of girl M​​​​​​g = 40 kg

Final velocity ( V​​​​​​2g​​​​) of girl in negative direction = 3m/s

Consider the frozen pond to be frictionless

Apply conservation of momentum

Initial momentum of girl and boy = final momentum of girl and boy

initial momentum of girl and boy is zero as they are at rest

= 0 = final momentum of girl + final momentum of boy ( P​​​​​​f)

= 0 = M​​​​​​​​​​g * (V​​​2g ) + P​​​​​f

0 = 40 * (-3) + P​​​​​​f

P​​​​​​f = 40*3

Final momentum of boy = 120 kg- m/s ( direction : positive direction )

0 0
Add a comment
Know the answer?
Add Answer to:
A boy of mass 60 kg and a girl of mass 40 kg are together and...
Your Answer:

Post as a guest

Your Name:

What's your source?

Earn Coins

Coins can be redeemed for fabulous gifts.

Log In

Sign Up

Not the answer you're looking for? Ask your own homework help question. Our experts will answer your question WITHIN MINUTES for Free.
Similar Homework Help Questions

  • A 65.0-kg boy and his 40.0-kg sister, both wearing roller blades, face each other at rest. The girl pushes the boy hard,...

    A 65.0-kg boy and his 40.0-kg sister, both wearing roller blades, face each other at rest. The girl pushes the boy hard, sending him backwards with velocity 2.90 m/s towards the west. Ignore friction. (a) Describe the subsequent motion of the girl. (b) How much potential energy in the girls body is converted into mechanical energy of the boy-girl system? (c) Is the momentum of the boy-girl system conserved in the pushing-apart process? If so, explain how that is possible...

  • A 30 KG GIRL AND A 25 KG BOY FACE EACH OTHER ON FRICTION-FREE ROLLER BLADES

    A 30 KG GIRL AND A 25 KG BOY FACE EACH OTHER ON FRICTION-FREE ROLLER BLADES. THE GIRL PUSHES THE BOY, WHO MOVES AWAY AT A SPEED OF 1.0 M/S. THE GIRLS SPEED IS?

  • A 44.7 kg girl and a 59.2 kg boy are on the surface of a frozen...

    A 44.7 kg girl and a 59.2 kg boy are on the surface of a frozen lake, 11.5 m apart. Using a rope, the girl exerts a horizontal 6.00 N force on the boy, pulling him toward her. Calculate the magnitude of the girl’s acceleration.

  • A boy with a mass 75kg and a girl with mass 45kg is on a boat...

    A boy with a mass 75kg and a girl with mass 45kg is on a boat at a speed of 10 m/s relative to the boat. Find the absolute velocity of the boy, girl and boat if a) boy jumps first b) girl jumps first c) they jump together

  • A boy of mass 43.1 kg is initially on a skateboard of mass 2.00 kg, moving...

    A boy of mass 43.1 kg is initially on a skateboard of mass 2.00 kg, moving at a speed of 10.4 m/s. The boy falls off the skateboard, and his center of mass moves forward at a speed of 10.9 m/s. Find the final velocity of the skateboard.

  • Two friends, Al and Jo, have a combined mass of 168 kg. At an ice skating...

    Two friends, Al and Jo, have a combined mass of 168 kg. At an ice skating rink they stand close together on skates, at rest and facing each other, with a compressed spring between them. The spring is kept from pushing them apart because they are holding each other. When they release their arms, Al moves off in one direction at a speed of 0.75 m/s, while Jo moves off in the opposite direction at a speed of 1.5 m/s....

  • A 40 kg boy is stationary on a 30 kg plank that is sliding at 5 m/s to the right across a...

    A 40 kg boy is stationary on a 30 kg plank that is sliding at 5 m/s to the right across a frictionless pond. The boy then turns and starts walking on the plank at arate of 4 m/s to the left, relative to the plank. What is the speed of the plank relative to the pond now ?

  • Q1 A small object with a momentum of magnitude 2.71 kg m/s approaches head-on a large...

    Q1 A small object with a momentum of magnitude 2.71 kg m/s approaches head-on a large object at rest. The small object bounces straight back with a momentum of magnitude 6.19 kg m/s. What is the magnitude of the small object's momentum change in kg m/s? Q2 A force acts on a 4.708 kg mass as follows: the force starts at zero and rises to 60.334 N linearly in 2.24 seconds, it remains at 60.334 N for another 5.756 seconds,...

  • A 5 g object moving to the right at 20 cm/s makes an elastic head-on-collision with...

    A 5 g object moving to the right at 20 cm/s makes an elastic head-on-collision with a 10 g object that is initially at rest. The acceleration of gravity is 9.8 m/s^2 Find the speed of the first object immediately after the collision (cm/s). An 80 kg boy skates at 0.5 m/s toward a 60 kg girl who is skating directly toward him at 0.5 m/s. After colliding, they hold each other and the bruised couple slides together. What is...

  • A girl on a skateboard (total mass of 40 kg) is moving at a speed of...

    A girl on a skateboard (total mass of 40 kg) is moving at a speed of 15 m/s at the bottom of a long ramp. The ramp is inclined at 18° with respect to the horizontal. If she travels 13.4 m upward along the ramp before stopping, what is the net frictional force (in N) on her? (Assume the positive direction is upward along the ramp. Indicate the direction with the sign of your answer.)

ADVERTISEMENT
Free Homework Help App
Download From Google Play
Scan Your Homework
to Get Instant Free Answers
Need Online Homework Help?
Ask a Question
Get Answers For Free
Most questions answered within 3 hours.
ADVERTISEMENT
ADVERTISEMENT