Well, the thing is: we don't really know, as we don't even know how many species there are on earth.
If we take a look at the estimates of <span>World Wide Fund for Nature, an organization that works toward combating species extinction, their estimates vary from 200 to 100 000 - but a probable number is 20 000 (d). </span>
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Answer:
<h2>400 J</h2>
Explanation:
The work done by an object can be found by using the formula
workdone = force × distance
From the question we have
workdone = 100 × 4
We have the final answer as
<h3>400 J</h3>
Hope this helps you
Answer:
Explanation:
a rigid object in uniform rotation about a fixed axis does not satisfy both the condition of equilibrium .
First condition of equilibrium is that net force on the body should be zero.
or F net = 0
A body under uniform rotation is experiencing a centripetal force all the time so F net ≠ 0
So first condition of equilibrium is not satisfied.
Second condition is that , net torque acting on the body must be zero.
In case of a rigid object in uniform rotation , centripetal force is applied towards the centre ie towards the line joining the body under rotation with the axis .
F is along r
torque = r x F
= r F sinθ
θ = 0 degree
torque = 0
Hence 2nd condition is fulfilled.
Answer:
<h2>15.25 N</h2>
Explanation:
A force of 
is acting on a wagon along the road. The wagon weights 
. Acceleration of the wagon is given as 
.
Consider the block as the system, the forces acting are Frictional force, Gravitational force, Normal reaction and External force applied by us.
Gravitational Force and Normal Reaction cancel out each other.
Net External Force = Mass of system/wagon 
Acceleration of wagon
has a negative sign because it opposes the motion of the wagon.
∴ Frictional Force = 15.25 N
