What class is that in ?????
The rays of light coming from the Sun are parallel to each other, so when they are reflected by the concave piece of glass (which acts as a concave mirror) they converge into the focus of the mirror, which is

The radius of curvature of a concave mirror is twice its focal length, so in this case it is:
Explanation:
Acceleration is defined as the rate of change of velocity with time. In most acceleration problems:
the given parameters will be;
Initial velocity
final velocity
time.
Using the equation below:
Acceleration = 
one can solve for acceleration. The unit is usually in m/s²
Learn more:
velocity brainly.com/question/10962624
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Answer:
29.75 revolutions
Explanation:
The kinematic formula for distance, given a uniform acceleration a and an initial velocity v₀, is

This car is starting from rest, so v₀ = 0 m/s. Additionally, we have a = 9.2/9.7 m/s² and t = 9.7 s. Plugging these values into our equation:

So, the car has travelled 44.62 m in 9.7 seconds - we want to know how many of the tire's <em>circumferences</em> fit into that distance, so we'll first have to calculate that circumference. The formula for the circumference of a circle given its diameter is
, which in this case is 47.8π cm, or, using π ≈ 3.14, 47.8(3.14) = 150.092 cm.
Before we divide the distance travelled by the circumference, we need to make sure we're using the same units. 1 m = 100 cm, so 105.092 cm ≈ 1.5 m. Dividing 44.62 m by this value, we find the number of revs is
revolutions
F = 1440 N. The repulsion force between two identical charges, each -8.00x10⁻⁵C separated by a distance of 20.0 cm is 1440 N.
The easiest way to solve this problem is using Coulomb's Law given by the equation
, where k is the constant of proportionality or Coulomb's constant, q₁ and q₂ are the charges magnitude, and r is the distance between them.
We have to identical charges of -8.00x10⁻⁵C, are separated by a distance of 20.0 cm, and we need to know the force of repulsion between the charges.
First, we have to convert 20.0 cm to meters.
(20.0 cm x 1m)/100cm = 0.20 m
Using the Coulomb's Law equation:

