The answer would be a.
a chemical change is a change to the chemical makeup of a substance so if the bonds are unchanged it would be a characteristic of a physical change
Answer:
(b) Yes, the earth gains momentum but the change in momentum of the earth is much lesser compared to that of everyone in the air. The resistance to motion (inertia of the earth), which is a function of its mass is so great that the earth's acceleration is small in the given time frame.
Explanation:
From Newton's second law which can be stated mathematically as
F = m(v-u)/t = ma.
By Newton's law of gravitation, there is a force between the earth and everyone in the air. This force is responsible for the change in momentum of everyone in the air and this force gives them an acceleration equal to g = 9.80m/s². By Newton's law of gravitation and Newton's third law of motion, this force is also equal to the force exerted by everyone on the earth.
For this to be true,
F = M (everyone) ×a (everyone) = M(earth) × a (earth).
And
a (earth) = {M (everyone) ×a (everyone) }/M (earth)
Then
a (earth) must be lesser than a (everyone) since M(earth) >> M(everyone).
a = change in momentum/ time
Therefore the earth will have a much lesser change in momentum which is the reason we won't notice the earth's movement.
Thank you for reading.
Answer:
i. 15.6 m/s
ii. I = 1.44 KNs
Explanation:
The impulse, I, on a body is the product of force applied on it and the time it acts.
i.e I = F x t
Impulse is sometimes expressed as the change in momentum of a body. It is measured in Ns.
i. mass, m, of the player = 92 kg
initial velocity of the player, u = 9.4 m/s
final velocity of the player, v = 6.2 m/s
Since he bounces back on hitting the pole, then the sign of initial and final velocities are of opposite sign.
So that,
change in velocity of the player = final velocity - initial velocity
= 6.2 - (-9.4)
= 6.2 + 9.4
= 15.6 m/s
change in velocity of the player is 15.6 m/s
ii. Impulse, I = m(v - u)
= 92 x 15.6
= 1435.2
Impulse on the player is 1.44 KNs.
Answer:No, the slope won't be too steep
Explanation:
Force is an external agency that causes a body to change its position while friction is a force that causes a body to slide over another. This force is called the frictional force (Ff). The force that causes a body to move is the moving force (Fm).
The slope will be too steep if the frictional force is greater than the moving force since the frictional force tends to oppose the moving force.
According to the explanation, we need to get Ff and compare with the moving force along the plane.
If Ff>Fm it means the slope will be too steep but if Ff<Fm, the slope won't be too steep and as such the body can easily be moved along the plane.
Resolving forces acting along the plane we have FmSintheta + Ff = Fm (FmSintheta and Ff are added because they act in the same direction along the plane)
Fm=50N, theta=5°
Imputing this into the formula to get Ff;
50sin5°+Ff =50
Ff= 50-50sin5°
Ff= 50-4.35
Ff= 45.65N
Since Ff<Fm, this means the slope is not too steep and as such the 30kg load can be moved along the plane easily.
