Answer:
The focal length of the concave mirror is -15.5 cm
Explanation:
Given that,
Height of the object, h = 20 cm
Radius of curvature of the mirror, R = -31 cm (direction is opposite)
Object distance, u = -94 cm
We need to find the focal length of the mirror. The relation between the focal length and the radius of curvature of the mirror is as follows :
R = 2f
f is the focal length
f = -15.5 cm
So, the focal length of the concave mirror is -15.5 cm. Hence, this is the required solution.
Answer:
Explanation:
Resistivity is given by where A is cross-sectional area, R is resistance, L is the length and is the reistivity. Substituting 0.0625 for R, 3.14 × 10-6 for A and 3.5 m for L then the resistivity is equivalent to
Answer:
Distance = 12 km
Displacement = 8.6 km
Explanation:
Given:
Chanice drives her scooter 7 kilometers North.
Chanice drives 5 kilometers east.
Let 'A' be initial position of Chanice, 'B' be the position when Chanice covered 7 km and 'C' be the final position.
Now, as per question:
AB = 7 km, BC = 5 km.
Therefore, total distance traveled by Chanice is equal to the sum of the distances AB and BC. So,
Total distance = AB + BC = 7 km + 5 km = 12 km
Now, displacement is the difference between the final position and initial position.
Final position is C and initial position is A. So, displacement is AC.
Therefore, displacement = AC
Now, using pythagoras theorem, we can find AC.
Therefore, her displacement is 8.6 km.
The distance between the orbits of two satellites is 7.97 m.
Explanation:
Johannes Kepler was the first to propose three laws for the planetary motion. According to him, the orbits in which planets are rotating are elliptical in nature and Sun is at the focus of the ellipse. Also the area of sweeping is same.
So based on these three assumptions, Kepler postulated three laws. One among them is Kepler's third law of planetary motion. According to the third law, the square of the time taken by a planet to cover a specified region is directly proportional to the cube of the major elliptical axis or the radius of the ellipse.
So,
Thus, for the geosynchornous satellite, as the time taken is 24 hours, then the radius or the major axis of this satellite is
Similarly, for the another satellite orbiting in time period of 12 hours, the major axis of this satellite is
So, the difference between the two radius will give the distance between the two orbits, 13.21-5.24 = 7.97 m.
So the distance between the orbits of two satellites is 7.97 m.