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
aniked [119]
3 years ago
11

A 20.0 kg crate sits at rest at the bottom of a 15.0-m-long ramp that is inclined at 34.0° above horizontal. A constant horizont

al force of 290 N is applied to the crate to push it up the ramp. While the crate is moving, the ramp exerts a constant frictional force on it that has magnitude 65.0 N.
(A) Is the total work done on the crate during its motion from the bottom to the top of the ramp?
Express your answer to three significant figures and include the appropriate units.
(B) How much time does it take the crate to travel to the top of the ramp?
Express your answer to three significant figures and include the appropriate units.

Physics
1 answer:
ankoles [38]3 years ago
7 0

Answer:

987 joules, 3.01s

Explanation:

(A)

from the attached diagram

net force, Fnet, pulling the crate up the ramp is given by

Fnet = FcosФ - WsinФ - Fr

where FcosФ is the component of horizontal force 290N resolved parallel to the plane

WsinФ = mgsinФ = component of the weight of the crate resolved parallel to the plane

Fr = constant opposing frictional force

Fnet = 290cos34⁰ - 20 × 9.8 × sin34° - 65

Fnet = 240.421 - 109.602 - 65

Fnet = 65.82N

Work done on the crate up the ramp, W, is given by

W = Fnet × d (distance up the plane)

W = 65.819 × 15

W = 987.285 joules

W = 987 joules (to 3 significant Figures)

(B)

to calculate the time of travel up the ramp

we use the equation of motion

s = ut + \frac{1}{2}at^{2}

where s = distance up the plane, 15m

u = Initial velocity of the crate, which is 0 for a body that is initially at rest

a = acceleration up the plane, given by

a = \frac{Fnet}{m}

where m = mass of the crate, 20 kg

now, a = \frac{65.819}{20} \\a = 3.291\frac{m^{2} }{s}

from, s = ut + \frac{1}{2}at^{2}

15 = 0*t + \frac{1}{2}* 3.291 * t^{2}

15 = 0 + 1.645t^{2}

15 = 1.645t^{2}

t = \sqrt{\frac{15}{1.645} }

t = 3.019

t = 3.01s (to 3 sig fig)

You might be interested in
A car traveling on a flat (unbanked), circular track accelerates uniformly from rest with a tangential acceleration of 1.85 m/s2
Tasya [4]

Answer:

Coefficient of friction = 0.836

Explanation:

If v be the speed after one quarter of the circular path

v² = 2as = 2 x 1.85 x 2πr/4 ; v²/r = 1.85 x 3.14 = 5.8

tangential acceleration = 5.8 m/s²

radial acceleration = v² /r = 5.8

total acceleration = √2 x 5.8

m x√2 x 5.8 = m x g xμ

μ = √2 x 5.8 / 9.8 = 0.836

7 0
3 years ago
Find the radioactivity of a 1 g sample of 226Ra given that <img src="https://tex.z-dn.net/?f=t_%7B1%2F2%7D%3D1620" id="TexFormul
dangina [55]

Answer:

Explanation:

No of atoms of Ra in 1 g of sample = 6.023 x 10²³ / 226

N = 2.66 x 10²¹

disintegration constant λ = .693 / half life

half life = 1620 x 365 x 60 x 60 x 24 = 5.1 x 10¹⁰ s

disintegration constant λ = .693 / 5.1 x 10¹⁰

radioactivity dn / dt = λN

= (.693 / 5.1 x 10¹⁰ )  x 2.66 x 10²¹

= .3614 x 10¹¹ per sec

= 3.614 x 10¹⁰ / s

6 0
2 years ago
When light passes from water into air, the light bends away from the normal. Question 4 options: True False
kykrilka [37]

Answer:

True

Explanation:

8 0
2 years ago
PLEASE HELP ASAP 2. Two rocks with a mass of 5 kilograms and 10 kilograms, respectively, fall freely from rest near
MrMuchimi

Answer:

i Think momentum

Explanation:

4 0
3 years ago
Which choice displays the effects of quantum mechanics? check all that apply
xxMikexx [17]

Answer:

A,B,C,D,F,G

Explanation:

Edge 2021

8 0
2 years ago
Other questions:
  • A long, straight wire carries a current of 8.60
    10·1 answer
  • ) A coin is tossed 13 times. a) How many different outcomes are possible? 2^8 b) How many different outcomes have exactly 4 head
    15·1 answer
  • A pendulum is made by letting a 4 kg mass swing at the end of a string that has a length of 1.5 meter. The maximum angle that th
    8·1 answer
  • Please help me feel in the blanks Giving 30 points
    15·1 answer
  • If you weigh 660 N on the earth, what would be your weight on the surface of a neutron star that has the same mass as our sun an
    12·1 answer
  • A motorist traveling at 12 m/s encounters a deer in the road 39 m ahead. If the maximum acceleration the vehicle’s brakes are ca
    10·1 answer
  • The knights of labor do not believe in arbitration but believed in strikes? true or false
    15·1 answer
  • Can anyone help me with this? <br>the question : find the value of the resistors​
    10·1 answer
  • What is the net force for this? (please don't forget it's direction and magnitude)​
    7·1 answer
  • Which type of radioactive decay has a positive charge?
    9·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!