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
mario62 [17]
3 years ago
9

The discovery of the Blombos cave suggests _________________

Physics
2 answers:
anyanavicka [17]3 years ago
5 0
The choices can be found elsewhere and as follows:

<span>a. copper alloy or bronze casting were first used in Sub Saharan Africa.
b. Islam became an economic and religious force in West and North Africa.
c. that abstract thought in humans occurred much earlier than once thought.
d. the French colonies were taken over before the third or fourth centuries.

I think the correct answer is option C. </span>The discovery of the Blombos cave suggests that abstract thought in humans occurred much earlier than once thought. 
Dmitrij [34]3 years ago
5 0

Answer:

that abstract thought in humans occurred much earlier than once thought.

Explanation:

You might be interested in
How long will it take a 2190 W motor to lift a 1.47 x 104 g box, 6.34 x 104 mm vertically.​
Rasek [7]

Answer:

t = 4.17 [s]

Explanation:

We know that work is defined as the product of force by distance.

W = F*d

where:

F = force [N] (units of Newtons)

d = distance = 6.34 x 10⁴ [mm] = 63.4 [m]

In order to find the force, we must determine the weight of the box, the weight can be determined by means of the product of mass by gravitational acceleration.

w = m*g

where:

m = mass = 1.47 x 10⁴ [g] = 14.7 [kg]

g = gravity acceleration = 9.81 [m/s²]

w = 14.7*9.81

w = 144.2 [N]

Therefore the work can be calculated.

W = w*d

W = 144.2*63.4

W = 9142.72 [J] (units of Joules)

Power is now defined in physics as the relationship of work at a given time

P = W/t

where:

P = power = 2190 [W]

t = time [s]

Now clearing t, we have.

t = W/P

t = 9142.72/2190

t = 4.17 [s]

6 0
3 years ago
A star is moving away from an observer at 1% of the speed of light. At what wavelength would the observer find an emission line
Ivan

Answer:

  λ = 5940 Angstroms

Explanation:

This is an exercise of the relativistic Doppler effect

        f’= f  √((1- v / c) / (1 + v / c))

Where the speed in between the strr and the observer is positive if they move away

Let's use the relationship

         c = λ f

         f = c /λ

We replace

              c /λ’ = c /λ  √ ((1- v / c) / (1 + v / c))

              λ = λ’ √ ((1- v / c) / (1 + v / c))

Let's calculate

             v = 0.01 c

             v = 0.01 3 10⁸

             v=  3 10⁶ m / s

             λ = 6000 √ [(1- 3 10⁶/3 10⁸) / (1+ 3 10⁶/3 10⁸)]

             λ = 6000 √ [0.99 / 1.01]

             λ = 5940 Angstroms

6 0
3 years ago
What is power?
hammer [34]
We can define power as the rate of doing work, it is the work done in unit time. The SI unit of power is Watt (W) which is joules per second (J/s). Sometimes the power of motor vehicles and other machines are given in terms of Horsepower (hp) which is approximately equal to 745.7 watts.


Power is the rate at which a force is applied to an object for example.current wire
4 0
3 years ago
Read 2 more answers
2. A mixture of mercury and copper is an example of
Olin [163]

Answer:

b

Explanation:

liquid and solid

hope that helps :)

4 0
3 years ago
Read 2 more answers
Explain the difference between mass and weight (in at least 2 sentences)
Irina-Kira [14]
Mass= is how big something is.
Weight= is how heavy something is.
They are different things because weight is talking about heavy... not how big it is.
5 0
3 years ago
Read 2 more answers
Other questions:
  • What is the ability to contract a muscle, or group of muscles, repeatedly without getting tired?
    12·2 answers
  • a ball weighing 100 n is shown suspended from a system of cords. what is the tension in the horizontal and angled cords at 50 de
    12·1 answer
  • A baseball player leads off the game and hits a long home run. The ball leaves the bat at an angle of 70.0 from the horizontal w
    14·1 answer
  • NEED HELP ASAP!! I AM MARKING BRAINLIEST!!
    9·1 answer
  • Why is density used to determine the identity of matter?
    14·1 answer
  • If a car has a mass of 4000 kg and the force applied to it is 10000 N. What is its acceleration?
    8·1 answer
  • Two blocks of masses 1.0 kg and 2.0 kg, respectively, are pushed by a constant applied force F across a horizontal frictionless
    8·1 answer
  • If a child pulls a sled through the snow with a force of 50 N exerted at an angle of 38° above
    12·1 answer
  • What is the speed of an object at rest?<br> a. 0.0 m/s<br> c. 9.8 m/s<br> b. 1.0 m/s<br> d. 9.81 m/s
    9·1 answer
  • Why do protons and neutrons need to be the same
    7·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!