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
morpeh [17]
3 years ago
14

3.

Physics
1 answer:
abruzzese [7]3 years ago
3 0

Answer:

I think they use it at night because they want to avoid involving themselves in road accident while crossing the street. When there are reflective strips on their clothes, drivers do notice them even at far ends of the street since the strips will reflect the rays from the car lights to the driver,hence, the driver notifies that there is a pedestrian crossing and therefore slows down.

You might be interested in
Based on the diagram which of the following statements is true of a helium atom
snow_lady [41]

Answer: Option 2

Explanation:

Option 1 is wrong because there are 2 protons and 2 neutrons in nucleus.

Option 3 is wrong because there are two electrons moving around nucleus.

Option 4 is wrong because electrons are negatively charged and are moving around the nucleus.

Option 5 is wrong because there equal amount of protons and electrons with 2 each.

8 0
3 years ago
(a) Calculate the absolute pressure at the bottom of a freshwater lake at a point whose depth is 30.0 m. Assume the density of t
Law Incorporation [45]

Answer:

(a) The absolute pressure at the bottom of the freshwater lake is 395.3 kPa

(b) The force exerted by the water on the window is 36101.5 N

Explanation:

(a)

The absolute pressure is given by the formula

P = P_{o} + \rho gh

Where P is the absolute pressure

P_{o} is the atmospheric pressure

\rho is the density

g is the acceleration due to gravity (Take g = 9.8 m/s^{2} )

h is the height

From the question

h = 30.0 m

\rho = 1.00 × 10³ kg/m³ = 1000 kg/m³

P_{o} = 101.3 kPa = 101300 Pa

Using the formula

P = P_{o} + \rho gh

P = 101300 + (1000×9.8×30.0)

P = 101300 + 294000

P =395300 Pa

P = 395.3 kPa

Hence, the absolute pressure at the bottom of the freshwater lake is 395.3 kPa

(b)

For the force exerted

From

P = F/A

Where P is the pressure

F is the force

and A is the area

Then, F = P × A

Here, The area will be area of the window of the underwater vehicle.

Diameter of the circular window = 34.1 cm = 0.341 m

From Area = πD²/4

Then, A = π×(0.341)²/4 = 0.0913269 m²

Now,

From F = P × A

F = 395300 × 0.0913269

F = 36101.5 N

Hence, the force exerted by the water on the window is 36101.5 N

5 0
2 years ago
Two ice skaters stand together. They push off and travel directly away from each other, the boy with a velocity of v = +0.35 m/s
DIA [1.3K]

Answer:

-0.55m/s

Explanation:

Given that: For the boy

Weight = 745N

Velocity = +0.35 m/s

Mass of the boy = ?

g = 9.81m/s^2

W = mg

745 = m×9.81

m = 75.94kg

For the girl

Given that:

Weight = 477 N

g = 9.81m/s^2

m = ?

W = mg

477 = m×9.81m/s^2

m = 48.62kg

To solve for the v of the girl, the two has to add up

48.62kg×v + 75.94kg×+0.35 m/s = 0

48.62v + 26.579 = 0

48.62v = - 26.579

v = -26.579/48.62

v = -0.5466

v = -0.55m/s

Hence, the velocity of the girl is -0.55m/s.

The negative sign is as a result of the two of them moving is opposite direction.

5 0
3 years ago
A ball is spun around in circular motion such that it completes 50 rotations in 25 s.
Leokris [45]

Answer:

(A) The period of its rotation is 0.5 s (2) The frequency of its rotation is 2 Hz.

Explanation:

Given that,

a ball is spun around in circular motion such that it completes 50 rotations in 25 s.

(1). Let T be the period of its rotation. It can be calculated as follows :

T=\dfrac{25}{50}\\\\T=0.5\ s

(2). Let f be the frequency of its rotation. It can be defined as the number of rotations per unit time. So,

f=\dfrac{50}{25}\\\\f=2\ Hz

Hence, this is the required solution.

3 0
3 years ago
In which region of the sun does energy move as waves that transfer from atom to atom
Artist 52 [7]

Answer:

Radiative zone

4 0
3 years ago
Read 2 more answers
Other questions:
  • What are you experiencing if you close your eyes and feel as if you are not moving
    15·1 answer
  • An object is falling from a height of 7.5 meters. At what height will its velocity be 7 meters/second?
    5·1 answer
  • The placebo effect best illustrates the impact of______on relief from pain.
    14·2 answers
  • You're driving your new sports car at 85 mph over the top of a hill that has a radius of curvature of 525 m.
    8·1 answer
  • The perimeter of a rectangle is 66 feet. Find its dimensions assuming that its length is 9 feet less than twice its width.
    6·1 answer
  • A pitcher throws a curveball that reaches the catcher in 0.64 s. The ball curves because it is spinning at an average angular ve
    7·1 answer
  • A 60 year old person has a threshold of hearing of 95.0 dB for a sound with frequency f=10,000 Hz. By what factor must the inten
    8·1 answer
  • At
    8·1 answer
  • What is the kinetic energy of a 5 kg object moving at 4 m/s
    15·1 answer
  • A sample of an ideal gas is heated, and its kelvin temperature doubles. What happens to the average speed of the molecules in th
    7·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!