Answer:
Be sure you understand two optics principles: the focal length of a convex mirror is NEGATIVE (by convention) and R / 2 = f.
Find f, take its negative, plug in the mirror equation and obtain Di = - 24 cm. This indicates that the image is virtual (as it should be in a convex mirror), is erect (as all virtual images are), is diminished (as it should be) and INSIDE the mirror as it should be.
Explanation:
The correct answer is - C. Crustal plates, crustal plates.
The movement of the crustal plates of the Earth is the reason why the geologic processes are occurring on our planet. With their movement, the crustal plates manage to create lot of pressure, open up gaps for the magma from the mantle, as well as make adjustments deeper into the ground.
Because of the adjustments deep into the ground, or rather the crust, lot of force is released, manifested as strong and very quick vibrations, better known as earthquakes.
The gaps that are opening between the plates let the magma reach the surface, thus enabling the volcanic activities on the planet.
The pressure from the plates' collision makes the land lift up slowly, and over time a mountain range starts to form because of the continuous lifting up of the area.
Answer: a) 10.4km
b) 0.62h
C) 17km/h
d) 9.1km/h
Explanation:
A) suppose you move in the positive direction of an x axis, from a first position of x1 = 0 to a second position of x2 at the station. That second position must be at x2 = 8.4 km + 2.0 km = 10.4 km.
B) time interval Dtwlk (= 0.50 h), but we don't know the driving time interval Dt/dr. However, we know that for the drive the displacement Dx/dr is 8.4 km and the average velocity vavg,dr is 70 km/h.
This average velocity is the ratio of the displacement for the drive to the time interval for the drive:
dv = dx/ dt
dt = dx/dv = 8.4/70 = 0.12h
t = ti + two
t = 0.12 + 0.50 = 0.62h
C) avg speed for the entire trip is the ratio of the displacement of 10.4 km for the entire trip to the time interval of 0.62 h for the entire trip.
Avg v = distance/time
10.4/0.62 = 16.8km/h
D) average speed is the ratio of the total distance you move to the total time interval you take to make that move. The total distance is 8.4 km + 2.0 km + 2.0 km = 12.4 km. The total time interval is 0.12 h + 0.50 h + 0.75 h = 1.37 h.
Avg speed = 12.4/1.37 = 9.1km/h
Answer:

Explanation:
The charge on one object, 
The distance between the charges, r = 0.22 m
The force between the charges, F = 4,550 N
Let q₂ is the charge on the other sphere. The electrostatic force between two charges is given by the formula as follows :

So, the charge on the other sphere is
.
Answer:
Spring C
Explanation:
According to Hooke's law, a force require to compress or extend a spring is directly proportional to the distance from its mean position.
The force of compression or expansion of the spring is given by the formula,
F = k x
Where,
k - spring constant. It is the constant value of the particular spring
x - distance of expansion or compression from mean position.
The x value of different spring,
A = 25 cm
B = 10 cm
C = 100 cm
D = 1 cm
The highest value of x for the same mass has the smallest spring constant according to the equation.
Hence, C has the smallest spring constant.