Explanation :
(1) Big bang : (1) The most accepted theory on the origin of the universe.
This theory shows the expanding of the universe from high density and high-temperature states.
(2) Steady state : (3) All is the same and will always stay the same.
Steady state means that the properties of any system remain the same always.
(3) Oscillating universe : (4) Agrees with the big bang theory but insists the universe expanded much quicker.
Oscillating universe theory is the result of big bang theory.
(4) Inflation Choices : (2) it's like an inflating and deflating balloon that never stops.
In cosmology, cosmic inflation or deflation is just the expanding and contraction of the universe.
So, the statements and the choices are related as:
(1)-(1)
(2)- (3)
(3)-(4)
(4)-(2)
Complete question is:
A 1200 kg car reaches the top of a 100 m high hill at A with a speed vA. What is the value of vA that will allow the car to coast in neutral so as to just reach the top of the 150 m high hill at B with vB = 0 m/s. Neglect friction.
Answer:
(V_A) = 31.32 m/s
Explanation:
We are given;
car's mass, m = 1200 kg
h_A = 100 m
h_B = 150 m
v_B = 0 m/s
From law of conservation of energy,
the distance from point A to B is;
h = 150m - 100 m = 50 m
From Newton's equations of motion;
v² = u² + 2gh
Thus;
(V_B)² = (V_A)² + (-2gh)
(negative next to g because it's going against gravity)
Thus;
(V_B)² = (V_A)² - (2gh)
Plugging in the relevant values;
0² = (V_A)² - 2(9.81 × 50)
(V_A) = √981
(V_A) = 31.32 m/s
For fundamental frequency of a string to occur, the length of the string has to be half the wavelength. That is,
1/2y = L, where L = length of the string, y = wavelength.
Therefore,
y = 2L = 2*0.75 =1.5 m
Additionally,
y = v/f Where v = wave speed, and f = ferquncy
Then,
v = y*f = 1.5*220 = 330 m/s
