The human ear is most sensitive to the sounds in what range?

Aleks04 [339]

Answer:

a) Watt is a derived unit because it's not a “base unit.”

b) The atomic clock is suitable for measuring time because natural atomic oscillations happen at a higher frequency and as a result they are more stable.

c) There is fluctuation in time measured by a pendulum clock because the pendulum rod changes in length slightly with changes in temperature, causing changes in the rate of the clock. An increase in temperature causes the rod to expand, making the pendulum longer, so its period increases and the clock loses time.

D) The weight of an object is more at pole and less at equator of the earth because the distance of the pole is less than the distance of the equator from the centre of the earth.

e) The weight of an object on the moon is about one-sixth the weight it would have on the earth because the moon's gravitation force is determined by the mass and the size of the moon. Hence, the weight of an object on the moon is 1/6th its weight on the earth.

4 0

3 years ago

A lightbulb has a power of 100 W and is used for 4 hours. A microwave has a power of 1200 W and is used for 5 minutes. How much

ladessa [460]

Answer:

a. E=1440KJ

b. E=360KJ

c. E=1.8 J

Explanation:

I have the power (Watts) is expressed as Energy (Joules) / Time (seconds), also I have to $1hour * \frac{60min}{1hour}*\frac{60s}{1min}\\1h=3600s$

so, for the lightbulb

$100W= \frac{Energy}{3600s*4}\\Energy=100W*14400s\\ E=1440000J =1440KJ$

Analogously, for the microwave

$1200W= \frac{Energy}{60s*5}\\Energy=1200W*300s\\ E=360000J =360KJ$

Now, I have to express the efficiency as Heat energy / power * 100 so $1.8= \frac{Heat Energy}{100W}*100\\Heat Energy=1.8J$

Done

4 0

4 years ago

9)A 64 kg parent and a 16 kg child meet at the center of an ice rink. They place their hands together and push. (A) Is the

Colt1911 [192]

Answer:

(A) The same

(B) More

(C) The magnitude of the parent's acceleration is 0.625 m/s²

Explanation:

The given parameters are;

The mass of the parent, m₁ = 64 kg

The mass of the child, m₂ = 16 kg

(A) By Newton's third law of motion, action and reaction are equal and opposite

Therefore, the action of the parent on the child is equal to the reaction of the child on the parent and vice versa

Therefore, the force experienced by the child is the same as the force experienced by the parent

(B) Newton's second law states that an objects acceleration is directly proportional to the applied force and inversely proportional to the mass of the object

Therefore, the parent and the child both experience the same force but the mass of the child is less than the mass of the parent and therefore, by Newton's second law, the acceleration of the child will be more than the acceleration of the parent for the same given force

(C) The acceleration of the child, a₂ = 2.5 m/s²

Let F₁ represent the force experienced by the parent, let F₂ represent the force experienced by the child and let a₁ represent the magnitude of the parent's acceleration

By Newton's third law, we have;

F₁ = F₂

Force, F = Mass, m × Acceleration, a

We can write, F = m × a

Therefore;

F₁ = m₁ × a₁ and F₂ = m₂ × a₂

∴ F₁ = F₂ gives;

m₁ × a₁ = m₂ × a₂

a₁ = (m₂ × a₂)/m₁ = (16 × 2.5)/64 = 0.625

∴ The magnitude of the parent's acceleration = a₁ = 0.625 m/s²

5 0

3 years ago

What would happen if an Asteroid hit earth?

svp [43]

Answer:

There would be tremendous earthquakes and tsunamis, followed by massive volcanism around the impact zone. The ozone layer would be destroyed. The oceans would turn acidic. The Sun would be blotted out, probably for decades.

Explanation:

Hope this helps!

4 0

3 years ago

Read 2 more answers

An Arrow (0.5 kg) travels with velocity 60 m/s to the right when it pierces an apple (1 kg) which is initially at rest. After th

Rom4ik [11]

Answer:

Velocity after collision will be 20 m/sec

Explanation:

We have given mass of arrow $m_1=0.5kg$