The wise and careful use of energy is called CONSERVATION
Answer:
5.3×10⁴ m/s
Explanation:
From the question,
Momentum = mass× velocity
M = mV................ Equation 1
Where M = momentum of the airplane, m = mass of the airplane, V = Velocity of the airplane
make V the subject of the equation
V = M/m.................. Equation 2
Given: M = 1.6×10⁹ Kg.m/s, m = 3.0×10⁴ kg
Substitute these values into equation 2
V = 1.6×10⁹/3.0×10⁴
V = 5.3×10⁴ m/s
Answer:
A waffle iron heated by coils
Explanation:
A waffle iron heated by coils - conduction
Food heated in a microwave oven - radiation
Pavement heated by the sun - radiation
A room heated by moving air - convection
Answer:
d. Boyle's
Explanation:
Boyle's Law: States that the volume of a fixed mass of gas is inversely proportional proportional to its pressure, provided temperature remains constant.
Stating this mathematically. this implies that:
V∝1/P
V = k/P, Where k is the constant of proportionality
PV = k
P₁V₁ = P₂V₂
Where P₁ and P₂ are the initial and final pressure respectively, V₁ and V₂ are the the initial and final volume respectively.
Hence the right option is d. Boyle's
In a stationary situation, the weight of person is

This is the weight "felt" by the scale, which is basically the normal reaction applied by the scale on the person, and which uses the value of g (9.81) as reference to convert the weight (602.8 N) into a mass (62 kg).
When the person is in the elevator, the scale says 77 kg. The scale is still using the same value of conversion (9.81), so the apparent weight "felt" by the scale is

This is the normal reaction applied by the scale on the person, and which is directed upward. Besides this force, there is still the weight W of the person, acting downward. So, if we use Newton's second law:


where a is the acceleration of the elevator. If we solve for a, we find

The negative sign means the acceleration is in the opposite direction of g (which we take positive), so it means the elevator is going upward.