Answer:
0.001 s
Explanation:
The force applied on an object is equal to the rate of change of momentum of the object:
where
F is the force applied
is the change in momentum
is the time interval
The change in momentum can be written as
where
m is the mass
v is the final velocity
u is the initial velocity
So the original equation can be written as
In this problem:
m = 5 kg is the mass of the fist
u = 9 m/s is the initial velocity
v = 0 is the final velocity
F = -45,000 N is the force applied (negative because its direction is opposite to the motion)
Therefore, we can re-arrange the equation to solve for the time:
Answer:
The speed of sound is affected by temperature and humidity. Because it is less dense, sound passes through hot air faster than it passes through cold air. ... The attenuation of sound in air is affected by the relative humidity. Dry air absorbs far more acoustical energy than does moist air.
Answer;
Q = 359.2-J
Explanation;
Given that;
Constants for mercury at 1 atm
Heat capacity of Hg(l) is 28.0 J/(mol*K)
melting point is 234.32 K
Enthalpy of fusion is 2.29 kJ/mol
17.7-g Hg / 200.6g/mol = 0.0882 mol Hg;
°C + 273 = 298 K;
2.29-kJ/mol = 2290-J/mol
Q = (m x ΔT x Cp) + (m x Hf)
Q = 0.0882-mol x (298 - 234.32) x 28.0-J/mol*K) + (0.0882-mol x 2290-J/mol)
Q = 157.26-J + 201.978-J
Q = 359.2-J
Q=359-J (3 sig fig allowed due to 17.7-g given in problem)
Remark
All the statements are correct except for B
B is wrong because the Force is inversely proportional to the square of the distance.
D is correct. That's what Newton saw when he watched the apple fall. The apple did all the moving.
A is correct. The formula is
F = G*m1*m2/r^2
If r is held constant the formula becomes
F = k * m1 * m2 where k = G/r^2
C is true as well, but it sure decreases in strength because of the distance and the smallness of G.
The answer will be 2,400,000 <span>kg⋅m/s</span><span>2</span>
