Answer:
-20000 kgm/s
Explanation:
Impulse: This can be defined as the product of the mass of a body and its change in velocity. The S.I unit of impulse is kgm/s.
Mathematically, impulse can be expressed as
I = m(v-u).............. Equation 1.
Where I = impulse applied to the car to bring it to rest, m = mass of the car, u = initial velocity of the car, v = final velocity of the car.
Given: m = 1000 kg, u = 20 m/s, v = 0 m/s ( to rest)
Substitute into equation 1
I = 100(0-20)
I = 1000(-20)
I = -20000 kgm/s
Hence the impulse applied to the car to bring it to rest = -20000 kgm/s
Compounds
Explanation:
Reactive elements such as alkali metals and halogens are found in nature only as compounds. Such elements are too unstable to remain as stable atoms, therefore they readily combine and form compounds.
- Compounds are formed when two atoms combines together to share electrons.
- They either lose, gain, or share electrons between themselves.
- In the end, they end up becoming more stable.
- This is the reason why atoms combine.
- Unstable elements are very reactive especially alkali metals and halogens.
- On their own, they are unstable and prefers to bond with other atoms in order to gain a measure of stability.
- This is why they are found in combined state in nature.
Learn more:
Compound brainly.com/question/10585691
Noble gases brainly.com/question/1781595
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Answer:
below
Explanation: When a liquid changes into a gas vaporization has occurred. The process can either occur due to boiling or evaporation. Boiling occurs when the vapor pressure of the liquid is raised (by heating) to the point where it is equal to the atmospheric pressure.
I am very sorry I don’t know
Answer:
b. v = 0, a = 9.8 m/s² down.
Explanation:
Hi there!
The acceleration of gravity is always directed to the ground (down) and, near the surface of the earth, has a constant value of 9.8 m/s². Since the answer "b" is the only option with an acceleration of 9.8 m/s² directed downwards, that would solve the exercise. But why is the velocity zero at the highest point?
Let´s take a look at the height function:
h(t) = h0 + v0 · t + 1/2 g · t²
Where
h0 = initial height
v0 = initial velocity
t = time
g = acceleration due to gravity
Notice that the function is a negative parabola if we consider downward as negative (in that case "g" would be negative). Then, the function has a maximum (the highest point) at the vertex of the parabola. At the maximum point, the slope of the tangent line to the function is zero, because the tangent line is horizontal at a maximum point. The slope of the tangent line to the function is the rate of change of height with respect to time, i.e, the velocity. Then, the velocity is zero at the maximum height.
Another way to see it (without calculus):
When the ball is going up, the velocity vector points up and the velocity is positive. After reaching the maximum height, the velocity vector points down and is negative (the ball starts to fall). At the maximum height, the velocity vector changed its direction from positive to negative, then at that point, the velocity vector has to be zero.
