The correct answer is A. an increase in Earth's average surface temperature.
While all of these are aspects of global warming, option A best summarizes it.
Answer:
These are the refractive defects of vision because they are caused by the incorrect refraction of light rays by the eye-lens. These defects of vision can be corrected by using suitable spherical lenses (convex lenses or concave lenses). These lenses are usually used in the form of eye-glasses or spectacles.
Explanation:
Answer:
800 kg/m³
Explanation:
I assume you want to find the density of the sphere?
Start with a free body diagram. There are three forces acting on the sphere: gravity pulling the sphere down, buoyancy pushing the sphere up, and tension pulling the sphere down.
Applying Newton's second law:
∑F = ma
B - W - T = ma
Since the sphere isn't accelerating, a = 0.
B - W - T = 0
B = W + T
We know that the tension is one-fourth the weight:
B = W + W/4
B = 5/4 W
B = 5/4 mg
Buoyant force is defined as:
B = ρVg,
where ρ is the density of the fluid, V is the displaced volume, and g is acceleration of gravity.
ρVg = 5/4 mg
ρV = 5/4 m
The mass of the sphere is equal to its density times its volume. Since the sphere is fully submerged, it's volume is the same as the volume of the displaced water.
ρV = 5/4 ρₓV
ρ = 5/4 ρₓ
ρₓ = 4/5 ρ
So the density of the sphere is 4/5 the density of the water. Water's density is 1000 kg/m³, so:
ρₓ = 4/5 (1000 kg/m³)
ρₓ = 800 kg/m³
Answer:
Momentum = 100 Kgm/s
Explanation:
Given the following data;
Speed = 72 km/h
Mass = 5 kg
To find the momentum of the stone;
First of all, we would have to convert the value of speed to meter per seconds.
Conversion:
72 km/h to m/s = (72 * 1000)/3600 = 20 m/s
Momentum can be defined as the multiplication (product) of the mass possessed by an object and its velocity. Momentum is considered to be a vector quantity because it has both magnitude and direction.
Mathematically, momentum is given by the formula;
Momentum = mass * velocity
Substituting the values into the formula, we have;
Momentum = 5 * 20
Momentum = 100 Kgm/s