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
Sergeeva-Olga [200]
3 years ago
11

A student is on a skateboard facing a wall. The student and skateboard have a mass of 75 kilograms. The student pushes off of th

e wall with a force of 100 Newtons. What is the force of the wall pushing back on the student? What is the acceleration of the student as she moves away from the wall?
Physics
1 answer:
almond37 [142]3 years ago
8 0

Answer:

F=-100N; a=1.3m/s^2

Explanation:

Force is being made by student, so wall counteracts that force by not moving so it is equally opposite.

You might be interested in
A pure substance has a/an
Evgesh-ka [11]

Answer:

Element or a compound.

Explanation:

6 0
3 years ago
An 80-kg hiker climbs to the top of a tall hill and builds up 470,000 J of gravitational potential energy. How high did the hike
nekit [7.7K]

Answer:

599 meters is the answer rounded to the nearest whole number and 599.489795918 meters is the complete answer

Explanation:

to find gravitational potential energy you multiply mass x acceleration due to gravity (always 9.8 on earth) x hight

since we know the gravitational potential energy and want to find out the hight, we take the gravitational potential energy (470,000) and divide it by the product of acceleration due to gravity x mass (9.8 x 80)

so how high the hiker climbed is equal to 470,000 divided by (9.8 x 80)

hight = 470,000 / (9.8 x 80)

hight = 470,000 / 784

hight = 599.489795918 meters

as for rounding, if the decimal is less than 5 you round "down" and keep the current whole number, if the decimal is 5 or greater you round "up" and add 1 to get your new number

5 0
3 years ago
Read 2 more answers
The flywheel of a steam engine runs with a constant angular velocity of 140 rev/min. When steam is shut off, the friction of the
ratelena [41]

Answer:

A) α = -1.228 rev/min²

B) 7980 revolutions

C) α_t = -8.57 x 10^(-4) m/s²

D) α = 21.5 m/s²

Explanation:

A) Using first equation of motion, we have;

ω = ω_o + αt

Where,

ω_o is initial angular velocity

α is angular acceleration

t is time the flywheel take to slow down to rest.

We are given, ω_o = 140 rev/min ; t = 1.9 hours = 1.9 x 60 seconds = 114 s ; ω = 0 rev/min

Thus,

0 = 140 + 114α

α = -140/114

α = -1.228 rev/min²

B) the number of revolutions would be given by the equation of motion;

S = (ω_o)t + (1/2)αt²

S = 140(114) - (1/2)(1.228)(114)²

S ≈ 7980 revolutions

C) we want to find tangential component of the velocity with r = 40cm = 0.4m

We will need to convert the angular acceleration to rad/s²

Thus,

α = -1.228 x (2π/60²) = - 0.0021433 rad/s²

Now, formula for tangential acceleration is;

α_t = α x r

α_t = - 0.0021433 x 0.4

α_t = -8.57 x 10^(-4) m/s²

D) we are told that the angular velocity is now 70 rev/min.

Let's convert it to rad/s;

ω = 70 x (2π/60) = 7.33 rad/s

So, radial angular acceleration is;

α_r = ω²r = 7.33² x 0.4

α_r = 21.49 m/s²

Thus, magnitude of total linear acceleration is;

α = √((α_t)² + (α_r)²)

α = √((-8.57 x 10^(-4))² + (21.49)²)

α = √461.82

α = 21.5 m/s²

4 0
3 years ago
You measure the power delivered by a battery to be 4.26 W when it is connected in series with two equal resistors. How much powe
gtnhenbr [62]

Answer:

<em>The power delivered by the battery is 17.04 W</em>

Explanation:

Power through a circuit is given as

P = IV    ....1

where P is the power

I is the current through the circuit

V is the voltage through the circuit

The voltage in a circuit is given as

V = IR    ....2

Let us take the value of each resistor as equal to R

when connected in series, the total resistance will be

R_{t} = R + R = 2R

If we assume constant voltage through the circuit, then from equation 2, the current in this case is

I = V/2R

If the resistors are connected in parallel, then the total resistance will be

\frac{1}{R_{t} } = \frac{1}{R} +

R_{t} = R/2

The current in this case will be increased since the resistance is reduced

I = 2V/R

comparing the two situations, we can see that the current increased when connected in parallel to a ratio of

\frac{2V}{R} ÷  \frac{V}{2R} =  

This means that the current increased 4 times

From equation 1, we can see that electrical power is proportional to the current at a constant voltage, therefore, the power will also increase by four times to

P = 4 x 4.26 = <em>17.04 W</em>

3 0
3 years ago
Two sources emit beams of light of wavelength 550 nm. The light from source A has an intensity of 10 μW/m2, and the light from s
alexira [117]

Answer:

<em>A) Beam B carries twice as many photons per second as beam A.</em>

Explanation:

If we have two waves with the same wavelength, then their intensity is proportional to their power, or the energy per unit time.

We also know that the amount of photon present in an electromagnetic beam is proportional to the energy of the beam, hence the amount of beam per second is proportional to the power.

With these two facts, we can say that the intensity is a measure of the amount of photon per second in an electromagnetic beam. So we can say that <em>beam B carries twice as more power than beam A, or Beam B carries twice as many photons per second as beam A.</em>

3 0
3 years ago
Other questions:
  • According to Ohm's law, a circuit with a high resistance _____. will have a low electric current will have a high electric curre
    10·2 answers
  • How many electrons will a single atom of sulfur with no charge and no bonds have in its valence shell?
    13·2 answers
  • With what new station is NASA going to support future Moon
    5·1 answer
  • 2. A rock is dropped off a bridge. How fast is the rock
    9·1 answer
  • Find avrage speed for a horse that traveled east 25 km in 4 hours
    8·1 answer
  • In order to do work, the force vector must be
    15·1 answer
  • 16. The sum of kinetic energies in an object.
    8·1 answer
  • Shelley is in an elevator that is traveling downward and slowing down at a rate of
    5·1 answer
  • SOMEONE, PLEASE HELP ME AS FAST AS YOU CAN, I WOULD GIVE MORE POINTS BUT THIS IS THE REST OF MY POINT, PLEASE SOMEONE WHO IS SUP
    5·1 answer
  • How can you degauss a magnet temporarily?
    5·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!