What units for time must be used in calculating power

If a thermometer measured the temperature in an oven as 400oF five days in a row when the temperature was actually 397oF, this m

aleksandrvk [35]

Answer:

It can be said to be reliable although it is not valid

Explanation:

This is because Reliability means an indicator of consistency, A measure should produce similar or the same results consistently if it measures the same quantity. So does the thermometer measures over 5days but it is not valid because it deviates from the real value

5 0

3 years ago

A person is riding on a Ferris wheel. When the wheel makes one complete turn, the net work done on the person by the gravitation

lara31 [8.8K]

Answer:

0

Explanation:

m = Mass of person

g = Acceleration due to gravity = 9.81 m/s²

d = Vertical height from the ground

F = Force = Weight = mg

Net work done would be

$W_n=W_{up}+W_{down}\\\Rightarrow W_n=Fdcos180+Fdcos0\\\Rightarrow W_n=-mgd+mgd\\\Rightarrow W_n=0$

Hence, the work done on the person by the gravitational force is 0

7 0

3 years ago

Why is Einstein's description of gravity called a theory, while Newton's is a law?

Ludmilka [50]

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.

4 0

3 years ago

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Two resistors, A and B, are connected in series to a 6.0 V battery. A voltmeter connected across resistor A measures a potential

mestny [16]

Answer:

Resistance of resistor A = 6.0 Ω and resistance of resistor B = 3.0 Ω

Explanation:

When the two resistors are in series, let V₁ = voltage in resistor A and R₁ = resistance of resistor A and V₂ = voltage in resistor B and R₂ = resistance of resistor B.

Given that V₁ + V₂ = 6.0 V and V₁ = 4.0 V,

V₂ = 6.0 V - V₁ = 6.0 V - 4.0 V = 2.0 V

Also, let the current in series be I.

So, V₁ = IR₁ and V₂ = IR₂

I = V₁/R₁ and I = V₂/R₂

equating both expressions, we have

V₁/R₁ = V₂/R₂

4.0 V/R₁ = 2.0 V/R₂

dividing through by 2.0 V, we have

2/R₁ = 1/R₂

taking the reciprocal, we have

R₂ = R₁/2

R₁ = 2R₂

From the parallel connection, let V₁ = voltage in resistor A and R₁ = resistance of resistor A and V₂ = voltage in resistor B and R₂ = resistance of resistor B. Since it is parallel, V₁ = V₂ = V = 6.0 V

Also, V₂ = I₂R₂ where I₂ = current in resistor B = 2.0 A and R₂ = resistance of resistor B

So, R₂ = V₂/I₂

= 6.0 V/2.0 A

= 3.0 Ω

R₁ = 2R₂

= 2(3.0 Ω)

= 6.0 Ω

So, resistance of resistor A = 6.0 Ω and resistance of resistor B = 3.0 Ω

6 0

3 years ago

Julie is cycling at a speed of 3.4 meters/second. If the combined mass of the bicycle and Julie is 30 kilograms, what is the kin

Anon25 [30]

Velocity=3.4m/sec
Mass=30kg
so kinetic energy=1/2mv^2
=1/2×30×3.4×3.4
=15×3.4×3.4
=15×11.56
=173.4 kg m per second square

6 0

3 years ago

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