TEST TOMMOROW (i was absent when problems were explained)

  • Thread starter 3dsmax
  • Start date
  • Tags
    Test
I'm not sure what you're talking about. Are you talking about #3 in the summary? In summary, the first problem involves a monkey and sled moving up an incline with given initial speed, mass, and coefficient of friction, and the question asks for the distance traveled. The second problem involves a skier starting from rest on an inclined hill with a given coefficient of friction and length, and the question asks for the distance traveled on a flat surface before coming to a stop. The equations used are conservation of energy, kinetic energy, potential energy, and work. Finally, the summary also mentions a third problem involving a discrepancy in calculation, but it is not clear what the problem is.
  • #1
3dsmax

Homework Statement


Okay i was absent for 2 days and missed how to do this stuff. And i got a test tommorow. So its not HW i just got to figure out how to do these problems. So i would really appreciate it if someone just did them and explained how. Cause i don't have much time to figure this out myself.

#1 In a circus performance, a monkey is strapped to a sled and both are given an initial speed of 4.00 m/s up a 20.0º incline track. The combined mass of the monkey and sled is 20.0 kg, and the coefficient of kinetic friction between the sled and incline is .200. How far up the incline do the monkey and sled move?

#2 A skier starts from rest at the top of a hill that is inclined at 10.5º with the horizontal. The hillside is 200.0 m long, and the coefficient of friction between snow and skis is .0750. At the bottom of the hill, the snow is level and the coefficient of friction is unchanged. How far does the skier move along the horizontal portion of the snow before coming to rest?

Homework Equations



(sigma)work = 1/2mf^2 - 1/2mvi^2



The Attempt at a Solution



I really don't know how to do these so please help me. Thank you so much to anyone that helps.
 
Physics news on Phys.org
  • #2
1. conservation of energy. The kinetic energy the monkey has at the start needs to be enough to do the work against gravity and friction.

2. again conservation of energy.

I'll give you a couple of equations to help you out:

K.E.=0.5*mv2

P.E=mgz (z=change in height)

work=force*distance

Good luck!
 
  • #3
for number 3 what is wrong with this approach:

x(196 N 36.9 N - 67.1 N) = 1/2(20 kg)(4 m/s^2)^2

x comes out to = 1.73 m

When the teacher told us it was 1.54 m

any idea?
 
  • #4
3dsmax said:
for number 3 what is wrong with this approach:

x(196 N 36.9 N - 67.1 N) = 1/2(20 kg)(4 m/s^2)^2

x comes out to = 1.73 m

When the teacher told us it was 1.54 m

any idea?

uhhh... I only see two problems
 

FAQ: TEST TOMMOROW (i was absent when problems were explained)

What topics will be covered on the test tomorrow?

The topics that will be covered on the test tomorrow will depend on what was covered in class when you were absent. It is best to ask your teacher or a classmate for this information.

Will the test be multiple choice or short answer?

This information will also depend on what your teacher has decided. It is best to ask your teacher or a classmate for this information.

How long will the test be?

The length of the test will vary depending on the number of problems or questions included. It is best to ask your teacher or a classmate for an estimate.

Are there any specific formulas or equations I need to know for the test?

If there are specific formulas or equations that need to be used on the test, your teacher should have provided them during the class when you were absent. If not, it is best to ask your teacher or a classmate for this information.

Can I use a calculator on the test?

This will also depend on your teacher's rules and the type of problems on the test. It is best to ask your teacher or a classmate for this information.

Back
Top