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
11

What is the speed of a car that traveled total of 75 km in 2 hours? *

Physics
2 answers:
Ainat [17]3 years ago
5 0

Answer:

speed=distance covered/time taken

=75/2

=37.5 km/hr

Explanation:

Furkat [3]3 years ago
5 0

average speed = distance move/ time taken

= 75km/2h

= 37.5km/h

You might be interested in
Please help ASAP, studying for finals.
Otrada [13]

Answer:

3)No, it's speed is constant.

7 0
3 years ago
A cube of oak wood with very smooth faces normally floats in water. Suppose you submerge it completely and press one face flat a
Rom4ik [11]

Answer:

There is no Buoyant force.

The block will only float to the surface when the pressed face is released

Explanation:

There would be no Buoyancy force on the cube of Oak wood when one face is pressed flat against the Bottom of a tank and this is simply because there is no upward force acting on the side of the cube that is pressed against the bottom

Buoyant force is simply caused by the pressure difference between the water over and under an object immersed in water . hence since there is no water pressure under the immersed cube there will be no pressure difference between the water under and over the cube of oak wood immersed in the water.

3 0
3 years ago
The word ‘radiation’ is used to describe particles or waves that are emitted by an object (known as a ‘source’) and carry energy
ozzi

Answer:

The word ‘radiation’ is used to describe particles or waves that are emitted by an object  

In physics, radiation is the emission or transmission of energy in the form of waves or particles through space or through a material medium. This includes: electromagnetic radiation, such as radio waves, microwaves, infrared, visible light, ultraviolet, x-rays, and gamma radiation (γ)

Explanation:

There are four major types of radiation: alpha, beta, neutrons, and electromagnetic waves such as gamma rays. They differ in mass, energy and how deeply they penetrate people and objects.

The first is an alpha particle. These particles consist of two protons and two neutrons and are the heaviest type of radiation particle. Many of the naturally occurring radioactive materials in the earth, like uranium and thorium, emit alpha particles

The second kind of radiation is a beta particle. It's an electron that is not attached to an atom. It has a small mass and a negative charge. Tritium, which is produced by cosmic radiation in the atmosphere and exists all around us, emits beta radiation. Carbon-14, used in carbon-dating of fossils and other artifacts, also emits beta particles. Carbon-dating simply makes use of the fact that carbon-14 is radioactive. If you measure the beta particles, it tells you how much carbon-14 is left in the fossil, which allows you to calculate how long ago the organism was alive.

The third is a neutron. This is a particle that doesn't have any charge and is present in the nucleus of an atom. Neutrons are commonly seen when uranium atoms split, or fission, in a nuclear reactor. If it wasn't for the neutrons, you wouldn't be able to sustain the nuclear reaction used to generate power.

The last kind of radiation is electromagnetic radiation, like X-rays and gamma rays. They are probably the most familiar type of radiation because they are used widely in medical treatments. These rays are like sunlight, except they have more energy. Unlike the other kinds of radiation, there is no mass or charge. The amount of energy can range from very low, like in dental x-rays, to the very high levels seen in irradiators used to sterilize medical equipment.

3 0
3 years ago
A hot-air balloon of diameter 12 mm rises vertically at a constant speed of 14 m/s. A passenger accidentally drops his camera fr
fgiga [73]

Answer:

<em>The balloon is 66.62 m high</em>

Explanation:

<u>Combined Motion </u>

The problem has a combination of constant-speed motion and vertical launch. The hot-air balloon is rising at a constant speed of 14 m/s. When the camera is dropped, it initially has the same speed as the balloon (vo=14 m/s). The camera has an upward movement for some time until it runs out of speed. Then, it falls to the ground. The height of an object that was launched from an initial height yo and speed vo is

\displaystyle y=y_o+v_o\ t-\frac{g\ t^2}{2}

The values are

\displaystyle y_o=15\ m

\displaystyle v_o=14\ m/s

We must find the values of t such that the height of the camera is 0 (when it hits the ground)

\displaystyle y=0

\displaystyle y_o+v_o\ t-\frac{g\ t^2}{2}=0

Multiplying by 2

\displaystyle 2y_o+2v_ot-gt^2=0

Clearing the coefficient of t^2

\displaystyle t^2-\frac{2\ V_o}{g}\ t-\frac{2\ y_o}{g}=0

Plugging in the given values, we reach to a second-degree equation

\displaystyle t^2-2.857t-3.061=0

The equation has two roots, but we only keep the positive root

\displaystyle \boxed {t=3.69\ s}

Once we know the time of flight of the camera, we use it to know the height of the balloon. The balloon has a constant speed vr and it already was 15 m high, thus the new height is

\displaystyle Y_r=15+V_r.t

\displaystyle Y_r=15+14\times3.69

\displaystyle \boxed{Y_r=66.62\ m}

3 0
3 years ago
Can an object be in mechanical equilibrium when only a single force acts on it? explain.
elena-s [515]
No because if there is a force, there is acceleration which means the object is getting faster.
3 0
3 years ago
Other questions:
  • A karate expert breaks a stack of bricks with his bare hand. If the force applied is 520 newtons and the impact time is 5.0 × 10
    13·2 answers
  • How many protons are there in any te atom
    12·1 answer
  • Does the frequency distribution appear to have a normal distribution using a strict interpretation of the relevant​ criteria? Te
    14·1 answer
  • 4.
    5·2 answers
  • Similar fossiles found all over the world true or false?
    8·1 answer
  • The preview of the scientific method
    11·1 answer
  • A physics student stands on the rim of the canyon and drops a rock. The student measures the time for it to reach the bottom to
    6·1 answer
  • A rock is dropped from the ceiling of a truck's cargo bay. with the truck moving at constant velocity, the rock strikes the floo
    5·1 answer
  • is it possible for the thermal energy in a bowl of cold water equal to the thermal energy in a bowl of hot water
    6·1 answer
  • What is the average depth of the oceanic crust? What percentage of our planet does it cover?
    8·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!