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
garik1379 [7]
3 years ago
8

A car speeds up as it rolls down a hill. Which is this an example of? A. positive acceleration B. negative acceleration C. relat

ive velocity
Physics
1 answer:
alina1380 [7]3 years ago
4 0
I believe it is A. positive acceleration since it is speeding up
You might be interested in
You hold a ruler that has a charge on its tip 6 cm above a small piece of tissue paper to see if it can be picked up. The ruler
Fed [463]

Answer:

9.81 × 10⁻¹⁰ C

Explanation:

Given:

Distance between the tissue and the tip of the scale, r = 6 cm = 0.06 m

Charge on the ruler, Q = - 12 μC = - 12 × 10⁻⁶ C

Mass of the tissue = 3 g = 0.003 Kg

Now,

The force required to pick the tissue, F = mg

where, g is the acceleration due to gravity

also,

The force between (F) the charges is given as:

F=\frac{kQq}{r^2}

where,

q is the charge on the tissue

k is the Coulomb's constant = 9 × 10⁹ Nm²/C²

thus,

mg=\frac{kQq}{r^2}

on substituting the respective values, we get

0.003\times9.81=\frac{9\times10^9\times(-12\times10^{-6})\times q}{0.06^2}

or

q = 9.81 × 10⁻¹⁰ C

Minimum charge required to pick the tissue paper is 9.81 × 10⁻¹⁰ C

3 0
3 years ago
A sled of mass m is being pulled horizontally by a constant horizontal force of magnitude F. The coefficient of kinetic friction
rusak2 [61]

I'll bite:

-- Since the sled's mass is 'm', its weight is 'mg'.

-- Since the coefficient of kinetic friction is μk, the force acting opposite to the direction it's sliding is    (μk) times (mg) .

-- If the pulling force is constant 'F', then the horizontal forces on the sled
are 'F' forward and (μk · mg) backwards.

-- The net force on the sled is  (F - μk·mg).
(I regret the visual appearance that's beginning to emerge,
but let's forge onward.)

-- The sled's horizontal acceleration is  (net force) / (mass) = (F - μk·mg) / m.
This could be simplified, but let's not just yet.

-- Starting from rest, the sled moves a distance 's' during time 't'.
We know that  s = 1/2 a t² , and we know what 'a' is.  So we can write

           s = (1/2 t²)  (F - μk·mg) / m    .

Now we have the distance, and the constant force.
The total work is (Force x distance), and the power is (Work / time).
Let's put it together and see how ugly it becomes.  Maybe THEN
it can be simplified.

Work = (Force x distance) =  F x  (1/2 t²)  (F - μk·mg) / m
 
Power = (Work / time) =    <em>F (t/2) (F - μk·mg) / m </em>

Unless I can come up with something a lot simpler, that's the answer.


To simplify and beautify, make the partial fractions out of the
2nd parentheses:
                                   <em> F (t/2) (F/m - μk·m)</em>

I think that's about as far as you can go.  I tried some other presentations,
and didn't find anything that's much simpler.

Five points,ehhh ?


4 0
3 years ago
Read 2 more answers
What is mesothermal climates
Snowcat [4.5K]

Answer:

Mesothermal regions have moderate climates. They are not cold enough to sustain a layer of winter snow but are also not remain warm enough to support flowering plants (and, thus, evapotranspiration) all year.

Explanation:

Please give the brainliest.

3 0
1 year ago
The centripetal force acting on the space shuttle
KIM [24]
The centripetal force acting on the space shuttle as it orbits Earth is equal to the shuttles momentum
4 0
3 years ago
How is heat transferred through radiation?
g100num [7]
A. Through the direct contact of particles
5 0
3 years ago
Other questions:
  • Where does energy go when an object hits the ground?
    10·1 answer
  • Which of the following is not a unit used to measure pressure?
    10·2 answers
  • An insulated lunch bag keeps food warm by
    6·2 answers
  • A runner jogs 1 km south to a school, then jogs 1km west to a restaurant. What is the position of the runner relative to the sch
    15·1 answer
  • The answer please it’s very simple this is 7th grade science
    13·2 answers
  • A ball is thrown horizontally from a cliff and hits the ground 4 seconds later 40 meters from the base of the cliff. How high wa
    6·2 answers
  • During World War I, the Germans had a gun called Big Bertha that was used to shell Paris. The shell had an initial speed of 0.88
    9·1 answer
  • b) Si la distancia entre el punto A y el punto B es de 650 metros aproximadamente y la estudiante tarda 15 minutos (1200 segundo
    7·1 answer
  • An Olympic high diver (mass = 70 kg) stands on a platform 20 m above the surface of the water. What is the diver's gravitational
    11·1 answer
  • Need some help plsss!
    10·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!