HomeworkLib
Question

A boy of mass 25.0 kg skateboards down a quarter pipe of radius 3.00 m. He...

A boy of mass 25.0 kg skateboards down a quarter pipe of radius 3.00 m. He starts from rest and there is no friction. a)Find his speed at the bottom b)Find the normal force at the bottom Example 7.5: if the speed at the bottom is instead 6.00 m/s, what was the work done by friction?

science   physics   
0 0
Add a comment Improve this question Transcribed image text
Next > < Previous
Sort answers by oldest

Homework Answers

Answer #1

a)

using energy conservation

0.5 m v^2 = m g h

0.5 v^2 = 9.8* 3

v = 7.668 m/s

======

b)

W = change in kE

W = 0.5* 25 * ( 6^2 - 7.668^2)

W = - 285 J

0 0
Add a comment
Know the answer?
Add Answer to:
A boy of mass 25.0 kg skateboards down a quarter pipe of radius 3.00 m. He...
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

  • s odott gi Page 204 Practice Problem 7.10: 53 - O-TOUS Find the skateboard's speed at...

    s odott gi Page 204 Practice Problem 7.10: 53 - O-TOUS Find the skateboard's speed at the bottom of the pipe if he is given a push at the top edge, so that he has an initial downward speed of 2.00 m/s. Answer: 7.93 m/s. EXAMPLE 7.10 Calculating speed along a vertical circle Here we will tackle a circular-motion problem using conservation of energy. Because the acceleration in this problem is not constant, we cannot approach it with the tools...

  • A block of mass m = 3.00 kg starts from the rest and slides down a...

    A block of mass m = 3.00 kg starts from the rest and slides down a 30.0∘ incline which is 3.60 m high. At the bottom, it strikes a block of mass M = 6.40 kg which is at rest on a horizontal surface (Figure 1). (Assume a smooth transition at the bottom of the incline.) The collision is elastic, and friction can be ignored. (A) Determine the speed of the block with mass m = 3.00 kg after the...

  • In a water park, a 40 kg boy slides down a water slide and into a...

    In a water park, a 40 kg boy slides down a water slide and into a pool of water. The boy starts from rest and hits the water in the pool at a speed of 14 m/s. If the work done on the boy by gravity is 6.5 kJ, how much work is done by friction? a) -4.50 kJ b) -3.62 kJ c) -2.58 kJ d) -5.79 kJ e) -1.38 kJ

  • 1) (Boy sledding on hill) A boy on a sled (total mass of boy-plus-sled m =...

    1) (Boy sledding on hill) A boy on a sled (total mass of boy-plus-sled m = 34 kg) slides down a straight, snowy incline of length 4-236 m angled at a-15° with the horizontal. At the base of the hill is a tiny dip, after which the boy begins sliding up another straight hill, traveling a lern gth L2-40 m at an angle of θ2-300 with the horizontal. The boy starts from rest and ends at rest. Only gravity and...

  • A solid, uniform disk of radius 0.250 m and mass 53.2 kg rolls down a ramp...

    A solid, uniform disk of radius 0.250 m and mass 53.2 kg rolls down a ramp of length 4.20 m that makes an angle of 15.0°with the horizontal. The disk starts from rest from the top of the ramp. (a) Find the speed of the disk's center of mass when it reaches the bottom of the ramp. m/s (b) Find the angular speed of the disk at the bottom of the ramp.

  • Jim rides his skateboard (starting at rest) down a ramp that is in the shape of...

    Jim rides his skateboard (starting at rest) down a ramp that is in the shape of a quarter circle with radius of 3.9 m. At the bottom of the ramp, Jim is moving at 7.5 m/s. Jim and his skateboard have a mass of 66.9 kg. How much work is done by friction as the skateboard goes down the ramp?

  • A solid, uniform disk of radius 0.250 m and mass 53.7 kg rolls down a ramp...

    A solid, uniform disk of radius 0.250 m and mass 53.7 kg rolls down a ramp of length 4.20 m that makes an angle of 12.0° with the horizontal. The disk starts from rest from the top of the ramp. (a) Find the speed of the disk's center of mass when it reaches the bottom of the ramp. m/s (b) Find the angular speed of the disk at the bottom of the ramp. rad/s

  • QUESTION 10 Tony Hawk is skating through a half-pipe with a radius of 4 m. Initially...

    QUESTION 10 Tony Hawk is skating through a half-pipe with a radius of 4 m. Initially he is in a crouched position with his center of mass 0.5 m above the surface of the half-pipe. He starts from rest with his center of mass a height of 3 m above the base of the half-pipe and experiences no loss of energy from friction as he moves. At the bottom of the half-pipe he stands up and lifts his arms into...

  • A 5.00-kg package slides 2.60 m down a long ramp that is inclined at 25.0 ∘...

    A 5.00-kg package slides 2.60 m down a long ramp that is inclined at 25.0 ∘ below the horizontal. The coefficient of kinetic friction between the package and the ramp is μk = 0.370. A)Calculate the work done on the package by friction. B)Calculate the work done on the package by gravity. C)Calculate the work done on the package by the normal force. D)Calculate the total work done on the package. E)If the package has a speed of 2.60 m/s...

  • A block of mass m = 3.00 kg slides down a 30.0∘ incline which is 3.60 m high. At the bottom, it s...

    A block of mass m = 3.00 kg slides down a 30.0∘ incline which is 3.60 m high. At the bottom, it strikes a block of mass M = 7.50 kg which is at rest on a horizontal surface (Figure 1). (Assume a smooth transition at the bottom of the incline). The collision is elastic, and friction can be ignored. A) Determine the speed of the block with mass m = 3.00 kg after the collision. B) Determine the speed...

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