Answer:
a) 0.31 rad/s
b) 100 J
c) 6.67 W
Explanation:
(a) the force would generate a torque of:

According to Newton 2nd law, the angular acceleration would be

It starts from rest, then after 15s it would achieve a speed of

(b) The distance angle swept by it is:

Hence the work by the child

c) Average power to work per time unit

Explanation:
As the earth travels around the sun in the elliptical orbit it must also be know that the axis of the earth is tilted as well.
- So when the earth is at the farthest point and the tilt of the earth's axis is towards the sun in that case the sun rays always incident on the surface of the earth near the poles and hence there is sunlight for the 24 hours of the day. But the intensity of these rays is very low because of the their slanted angle of incident. In other words the same sun rays cover a larger area and the luminous intensity is reduced.
- When the earth is near to the sun we have an increased average temperature of the day during that phase giving us an experience of summer season and vice-versa is the condition in winter seasons. The tilt of the earths axis is responsible for variation in extremities of the seasons with respect to the geographical location.
I believe the answer is C
Answer:
Explanation:
Total length of the wire is 29 m.
Let the length of one piece is d and of another piece is 29 - d.
Let d is used to make a square.
And 29 - d is used to make an equilateral triangle.
(a)
Area of square = d²
Area of equilateral triangle = √3(29 - d)²/4
Total area,

Differentiate both sides with respect to d.

For maxima and minima, dA/dt = 0
d = 8.76 m
Differentiate again we get the

(a) So, the area is maximum when the side of square is 29 m
(b) so, the area is minimum when the side of square is 8.76 m
C.an equal and opposite reaction