Answer:
The tension on the string is 
Explanation:
From the question we are told that
The mass of the rock is 
The density of the rock is 
Generally the volume of the rock is mathematically evaluated as
substituting values
The volume of the rock immersed in water is
substituting values
mass of water been displaced by the this volume is
According to Archimedes principle
=> 
The weight of the water displace is
The actual weight of the rock is
The tension on the string is
substituting values
Conduction is slower in liquids and gases.
Liquids it is convection which transmits more heat.. quicker...
Materials which are good conductors of thermal energy are called thermal conductors.
metals are good thermal conductors.
Construct a vector diagram. It will be a right-angled triangle. One vector (the hypotenuse) represents the heading of the boat, one represents the current and one represents the resultant speed of the boat, which I'll call x. Their magnitudes are 20, 3 and x. Let the required angle = theta. We have:
<span>theta = arcsin(3/20) = approx. 8.63° </span>
<span>The boat should head against the current in a direction approx. 8.63° to the line connecting the dock with the point opposite, or approx. 81.37° to the shore line. </span>
<span>x = sqrt(20^2 - 3^2) </span>
<span>= sqrt(400 - 9) </span>
<span>= sqrt 391 </span>
<span>The boat's crossing time = </span>
<span>0.5 km/(sqrt 391 km/hr) </span>
<span>= (0.5/sqrt 391) hr </span>
<span>= approx. 0.025 hr </span>
<span>= approx. 91 seconds</span>
Answer:
they were hunter gatherers
Explanation:
