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
svetoff [14.1K]
3 years ago
8

A boy in a wheelchair (total mass 54.5 kg) has speed 1.40 m/s at the crest of a slope 2.10 m high and 12.4 m long. At the bottom

of the slope his speed is 6.60 m/s. Assume air resistance and rolling resistance can be modeled as a constant friction force of 41.0 N. Find the work he did in pushing forward on his wheels during the downhill ride.
Physics
1 answer:
babymother [125]3 years ago
3 0

Answer:

630.75 j

Explanation:

from the question we have the following

total mass (m) = 54.5 kg

initial speed (Vi) = 1.4 m/s

final speed (Vf) = 6.6 m/s

frictional force (FF) = 41 N

height of slope (h) = 2.1 m

length of slope (d) = 12.4 m

acceleration due to gravity (g) = 9.8 m/s^2

work done (wd) = ?

  • we can calculate the work done by the boy in pushing the chair using the law of law of conservation of energy

wd + mgh = (0.5 mVf^2) - (0.5 mVi^2) + (FF x  d)

wd = (0.5 mVf^2) - (0.5 mVi^2) + (FF x  d) - (mgh)

where wd = work done

m = mass

h = height

g = acceleration due to gravity

FF = frictional force

d = distance

Vf and Vi = final and initial velocity

wd =  (0.5 x 54.5 x 6.9^2) - (0.5 x 54.5 x 1.4^2) + (41 x 12.4) - (54.5 X 9.8 X 2.1)            

wd = 630.75 j

You might be interested in
Road rage is an aggressive driving incident where the driver has:
WARRIOR [948]
I would say that it would be A.) Been insulted. This is because you are angered by someone else. It does not necessarily mean that something has de-escelated, you've lost control of your car, or you've nothing to lose. Hopefully that helps. :)

5 0
3 years ago
Find the orbital speed v for a satellite in a circular orbit of radius R.Express the orbital speed in terms of G, M, and R.
AlekseyPX
<h2>Answer:V=\sqrt{G\frac{M}{R}}  </h2>

The velocity of a satellite describing a circular orbit is <u>constant</u> and defined by the following expression:

V=\sqrt{G\frac{M}{R}}     (1)

Where:

G is the gravity constant

M the mass of the massive body around which the satellite is orbiting

R the radius of the orbit (measured from the center of the planet to the satellite).

Note this orbital speed, as well as orbital period, does not depend on the mass of the satellite. I<u>t depends on the mass of the massive body.</u>

In addition, this orbital speed is constant because at all times <u>both the kinetic energy and the potential remain constant</u> in a circular (closed) orbit.

5 0
4 years ago
For a snowboard jumper in the air, what force or forces will be most important for modeling the motion?
Reptile [31]

Answer: Gravitational force and drag force

Explanation:

For a snowboard jumper in the air, two forces would be acting. One in the downward direction- the gravitational pull and second in the opposite direction to the motion, the drag force due to air. If the snowboard jumper jumps in the air at a certain angle with the horizontal. The forces are written as the sum of vertical and horizontal components. Hence, for the modeling the motion, gravitational force and drag force are important,

4 0
3 years ago
A fixed system of charges exerts a force of magnitude 22 N on a 4.0 C charge. The 4.0 C charge is replaced with a 8.0 C charge.
Karo-lina-s [1.5K]

Answer:

44 N

Explanation:

The electrostatic forces between two charges is given by:

F=k\frac{q_1 q_2}{r^2}

where

k is the Coulomb's constant

q1 and q2 are the two charges

r is their separation

We notice that the force is directly proportional to the charges.

In this problem, initially we have a force of

F = 22 N

on a q2 = 4.0 C, exerted by a charge q1.

If the charge is doubled,

q2 = 8.0 C

This means that the force will also double, so it will be

F=22 N \cdot 2 = 44 N

3 0
3 years ago
Roughly to what height would a 5 kg stone need to be raised in order to have the same stored energy as the energy stored in the
hoa [83]

8.16m is the required height, a 5kg stone need to be raised.

One sort of potential energy is gravitational potential energy, which is equal to the product of the object's mass (m), the gravitational acceleration (g), and the object's height (h) as measured in relation to the ground's surface (the body).

We obtain the formula by considering the work done in raising a mass m through a height h.

Work in elevating mass m through height h is equal to force times distance.

The force must be greater than the mass m's weight, hence F = mg.

Work done = mgh = gravitational potential energy

Energy =  Mass of the object × gravitational acceleration × height.

Mass of the stone = 5kg

Equating ;

∴ 400 J = 5 kg × 9.8 m/s² × height

  Height = 8.16 m

Therefore, 8.16m is the required height.

Learn more about energy here:

brainly.com/question/1242059

#SPJ1

8 0
2 years ago
Other questions:
  • Assume that Parker Company will receive SF200,000 in 360 days. Assume the following interest rates:
    14·1 answer
  • A glass dropped on the floor is more likely to break if the floor is concrete
    6·1 answer
  • The heart rate that indicates your fitness level is the
    6·1 answer
  • Oil explorers set off explosives to make loud sounds, then listen for the echoes from underground oil deposits. Geologists suspe
    14·2 answers
  • Cognitive changes that accompany depression include
    15·1 answer
  • A 0.250 kg mass is attached to a spring with k=18.9 N/m. At the equilibrium position, it moves 2.89 m/s. What is the amplitude o
    15·1 answer
  • Drag each tile to the correct box a chemical reaction takes place in which energy is released arrange the reactions characterist
    8·1 answer
  • Why can you hear a man's voice around the corner of a building even if you can't see him?
    12·1 answer
  • What is the weight in Newtons of a ball with a mass of 7.77 kg?
    7·1 answer
  • What kind of electromagnetic waves are used by an FM radio?.
    8·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!