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3 years ago

15

If someone drops a cup, it falls to the ground. Why doesn't the gravitational force between the person's hand and the cup keep t

he cup from falling?

1 answer:

Genrish500 [490]3 years ago

5 0

Answer:

The gravity from the person's hand is weaker than the gravity from the pull of the earth

Explanation:

The gravity from the person's hand is weaker than the gravity from the pull of the earth

You might be interested in

If the earth’s tilt on it axis were to increase by 20 degrees, what would happen to earth?

Triss [41]

Each pole would become tropical during summer, but be horribly cold during winter, far colder than they are now. But the equator would be in perpetual twilight during two seasons—and summer the opposing two.

4 0

3 years ago

When the body requires an increased blood flow rate in a particular organ or muscle, it can accomplish this by increasing the di

horsena [70]

Answer: The percentage increase in diameter is 19%

Explanation:

<em>Using Poiseuille's law which states that Flow rate , Q = ΔPπr⁴/8ηl</em>

<em>where ΔP is pressure difference, π is a constant, r is the radius which is half of the diameter, η is viscosity of blood, l is length of blood vessel</em>

Let Q₁ be the intitial flow rate, Q₂ the final flow rate,r₁ and r₂ the initial and final radius.

Note: r = d/2, therefore, r₁⁴ = d₁⁴/16 r₂⁴ = d₂⁴/16

Also, Q₂ = 2Q₁, since the flow rate is doubled

Since all factors except diameter is constant, d₂⁴/16 = 2d₁⁴/16

d₂⁴/16 = d₁⁴/8

multiply both sides of the equation by 16

d₂⁴ = 2d₁⁴

taking the fourth root of both sides

d₂ = 1.19*d₁

d₂ - d₁ = 1.19d₁ - d₁

d₂ - d₁ = d₁(1.19 - 1)

d₂ - d₁ = 0.19d₁

d₂ - d₁/d₁ = (0.19d₁/d₁)*100%

(d₂ - d₁/d₁)*100% = 19%

Therefore, the percentage increase in diameter is 19%

3 0

4 years ago

7. A 1.0 kg metal head of a geology hammer strikes a solid rock with a velocity of 5.0 m/s. Assuming all the energy is retained

marta [7]

The increase in temperature of the metal hammer is 0.028 ⁰C.

The given parameters:

<em>mass of the metal hammer, m = 1.0 kg</em>
<em>speed of the hammer, v = 5.0 m/s</em>
<em>specific heat capacity of iron, 450 J/kg⁰C</em>

The increase in temperature of the metal hammer is calculated as follows;

$Q = K.E\\\\mc \Delta T = \frac{1}{2} mv^2\\\\\Delta T = \frac{v^2}{2 c}$

where;

<em>c is the </em><em>specific heat capacity</em><em> of the metal hammer</em>

<em />

Assuming the metal hammer is iron, c = 450 J/kg⁰C

$\Delta T = \frac{5^2}{2 \times 450} \\\\\Delta T = 0.028 \ ^0C$

Thus, the increase in temperature of the metal hammer is 0.028 ⁰C.

Learn more about heat capacity here: brainly.com/question/16559442

8 0

3 years ago

A cricketer moves his hands backwards when holding a catch

lisov135 [29]

By doing this he increases the time due to which the rate of change momnetemdecreases. that means the ball comes to rest gently and does not hurt the fielder. but, if does not move his hand backwards, then the ball would come to rest in a fraction of second with a high rate of change of momentum. the ball will exert a lot of force on the hands of the fielder which will hurt him.

3 0

3 years ago

In April 1974, Steve Prefontaine completed a 10.0 km race in a time of 27 min , 43.6 s . Suppose "Pre" was at the 7.43 km mark a

Novay_Z [31]

Answer:

Acceleration, a = 0.101 m/s²

Explanation:

Average speed = total distance / total time.

At the 7.43km mark, total distance = 7.43km or 7430m

Total time = 25 * 60 s = 1500s

Average speed = 7430m/1500s = 4.95m/s

He then covers (10 - 7.43)km = 2.57 km = 2570 m

in t = 27m43.6s - 25min = 2m43.6s = 163.6 s

Then he accelerates for 60 s, and maintains this velocity V, for the remaining (163.6 - 60)s = 103.6 s.

From V = u + at; V = 4.95m/s + a *60s

Distance covered while accelerating is

s = ut + ½at² = 4.95m/s * 60s + ½ a *(60s)² = 297m + a*1800s²

Distance covered while at constant velocity, v after accelerating is

D = velocity * time

Where v = 4.95m/s + a*60s

D = (4.95m/s + a*60s) * 103.6s = 512.82m + a*6216s²

Total distance covered after initial 7.43 km, S + D = 2570 m, so

2570 m = 297m + a*1800s² + 512.82m + a*6216s²

2570 = 809.82 + a*8016

a = 809.82m / 8016s² = 0.101 m/s²

8 0

3 years ago