Answer:
50 h
Explanation:
The heat required (Q) to heat the water can be calculated using the following expression.
Q = c × m × ΔT = (4.184 kJ/kg.°C) × 1000 kg × (200°C - 60°C) = 5.9 × 10⁵ kJ
where,
c: specific heat capacity
m: mass
ΔT: change in the temperature
The solar collector has an area of 6 m² and the intensity delvered by sunlight is 550 W/m². The power (P) submitted by the collector is:
6 m² × 550 W/m² = 3 × 10³ W
The energy collected is transformed into heat. We know that:
P = E/t = Q/t
where
t: time
t = Q/P = 5.9 × 10⁸ J / (3 × 10³ J/s) = 2 × 10⁵ s × (1 h / 3600 s) = 50 h
Given :
A rope 6m long is fixed at one end, the other end is attached to a light string so that it is free to move.
The speed of waves on the rope is 18 m/s.
To Find :
The frequency of the second harmonic.
Solution :
We know, for second harmonic wave :
Wavelength = Length of rope
Now, we know frequency is given by :
Therefore, the frequency of the second harmonic is 3 s⁻¹.
Albert Einstein came up with the theory of general relativity to explain the law of gravity, whilst Newton's three laws of gravity is universal. To understand this further, it's best to understand it in scientific terms.
The weird thing about science is that words that are used in a colloquial sense may have a completely opposite definition in scientific terms.
A law in science is a constant and invariable statement that is universal. Wherever you may be in the universe, Newton's three laws of gravity will always be applied.
The word "theory" doesn't imply conjecture or an idea someone made up after a night of drinking. In science, a theory is the highest level of certainty behind mathematical proof -- which isn't even a part of science, obviously. A theory has to be substantiated by all available evidence and contradicted by none. All theories also have to have to be falsifiable. For this reason, theories can never be proven. Einstein's theory of general relativity has great predictive power, but in some cases, the predictions aren't always constant. Theories are often revised to fit new available evidence.
Answer:
<em>Magnitude of the Frictional force is 200 N</em>
Explanation:
The frictional force is the force that tries to oppose relative motion between two surfaces that are contacting. The coefficient of static friction is the coefficient of friction of a body that is not moving.
Newton's third law of motion states that action and reaction forces are equal and opposite. So the frictional force felt on the filing cabinet will be equal to the applied force pulling the cabinet.
Frictional force = Force applied
Force applied = 200 N
Therefore, the magnitude of the friction force on the filing cabinet is 200 N
