Answer:
Fk = 21.645N
Explanation:
Let Fb be Force of block and thus;
Fb= mg where m is mass of block and g is acceleration due to gravity
Thus Fb= 9kg x 9.81N/kg = 88.29 N
Now, the question says this force Fb rests at an inclined plane [email protected] 30° angle
Thus;
Force parallel to inclined plane = 88.29 x sin30° = 44.145 N.
Force perpendicular to the inclined plane = 88.29 x cos30 = 76.46 N
Now, when an object is falling freely, we know that
h = (1/2)at^(2)
From the question, the height is 5m and t= 2 seconds
Thus;
5 = (1/2)a(2)^(2)
2a = 5 and thus,
a = 5/2 = 2.5 m/s^(2)
Now, in inclined planes, perpendicular force - kinetic friction force = Resultant force
Thus let perpendicular be Fp and kinetic friction force be Fk and so;
Fp - Fk = F
F= ma = 9 x 2.5 = 22.5N
Thus, 44.145 - Fk = 22.5
Thus, Fk = 44.145 - 22.5 = 21.645N
Answer:
D
Explanation:
A is incorrect because it would actually increase the population...
B is incorrect because other birds do not matter, it is only whooping cranes...
C is incorrect because it would also increase the population.
The time it takes for the Moon to rotate once around its axis is equal to the time it takes for the Moon to orbit once around Earth
An insulator is a material that does not allow a transfer of electricity or energy. Materials that are poor thermal conductors can also be described as being good thermal insulators.