Ask question

Ask question

All categories

3 years ago

15

A cat lies on the floor. can you say that no force acts on the cat? or is it correct to say that no net force acts on the cat? e

xplain.

1 answer:

DIA [1.3K]3 years ago

5 0

Odd though it seems at first, gravity is pulling the cat down while the floor is pushing the cat up - in equal amounts. Forces are absolutely acting on the cat but they balance - so there is no net force.

You might be interested in

A parallel-plate capacitor is constructed of two horizontal 15.6-cm-diameter circular plates. A 1.4 g plastic bead with a charge

MrRissso [65]

Answer: The upper plate is positive charged. b) 0.53 µC.

Explanation:

As the plastic bead is suspended between the two plates, the external forces acting upon it must be equal and opposite each other.

The external forces acting upon it, are gravity (always downward) and the on due to electric Field, which must aim upwards, to keep the system in equilibrium.

As the charge on which the force must be act is a negative charge, this means that the force and the electric field must aim in opposite direction, so the electric field must point from the upper plate to the lower one.

This means that the upper plate must be positive charged.

We can find out the magnitude of the electric field, as follows:

E = mg / q = 0.0014 Kg. 9.8 m/s2 / 4.4 x 10⁻⁹ C = 3.12. 10⁶ V/m

b) In order to know the charge on the positive charged plate, we know that the capacitance , by definition, is as follows:

C = Q /V

It can be showed, that for a parallel plate capacitor, the capacitance can be expressed as a relationship of geometric parameters, as follows:

C = ε₀ A / d

But, V and E are related linearly by the expression:

V= E. d

Equating both expressions for C, we have:

Q / E.d = ε₀ A / d , so we can simplify and solve for Q, as follows:

Q = ε₀ A E = 8.85. 10⁻¹² farad/m. π (0.156)2 . ¼. 3.12. 10⁶ V/m = 0.53 µC

4 0

4 years ago

Which of the following best describes the gas trapped in a sealed balloon?

aliina [53]

"C) The movement of the gas particles keeps the balloon inflated" best describes the gas trapped in a sealed balloon, although the movement varies with the heat of the gas.

4 0

3 years ago

A 817 kg car has four 8.91 kg wheels. When the car is moving, what fraction of the total kinetic energy of the car is due to rot

KATRIN_1 [288]

Answer:

0.0107

Explanation:

We know that

The rotational kinetic energy due to four wheel is

1/2ဃ²I x 4

So

1/4mR²(v/R)² = mv²

But kinetic energy along straight path of the car is 1/2mv²

=> 1/2( 817)v ²

Kc= 408.5v²

So The fraction of total kinetic energy that is due to rotation of the wheel about their axis

Is Kw/Kw+Kc

and Kw = 1/2* 8.91v²= 4.45v²

So 4.45v²/ 4.45v²+ 408.5v²

= 0.0107 as fraction of total kinetic energy

8 0

3 years ago

The orbital motion of Earth around the Sun leads to an observable parallax effect on the nearest stars. For each star listed, ca

Murrr4er [49]

Answer:

Following are the answer to this question:

Explanation:

Formula:

$D(PC) =\frac{1}{parallax}\\\\D(av)=D(PC) \times 20.626\ J$

Calculating point A:

when the value is $0.38$

$\to 0.38 \toD(PC)= \frac{1}{0.38}\\\\$

$=2.632$

$\to D(a.v) = \frac{1}{0.38} \times 206265\\$

$=542,802.6$

Calculating point B:

when the value is $0.75$

$\to D(PC)=\frac{1}{0.75}$

$=1.33$

$\to D(a.v) = \frac{1}{0.75} \times 206265\\$

$=275,020$

Calculating point C:

when the value is $0.28$

$\to D(PC)=\frac{1}{0.28}$

$=3.571$

$\to D(a.v) = \frac{1}{0.28} \times 206265\\$

$=736660.7$

Calculating point D:

when the value is $0.42$

$\to D(PC)=\frac{1}{0.42}$

$=2.38$

$\to D(a.v) = \frac{1}{0.42} \times 206265\\$

$=490910.7$

Calculating point E:

when the value is $0.31$

$\to D(PC)=\frac{1}{0.31}$

$=3.226$

$\to D(a.v) = \frac{1}{0.31} \times 206265\\$

$=665370.97$

6 0

3 years ago

What does Newton's 2nd Law explain?

kow [346]

Answer:

C. Why you must push harder to move a car farther.

Explanation:

Newton's Second Law of Motion states that the acceleration of a physical object is directly proportional to the net force acting on the physical object and inversely proportional to its mass.

Mathematically, it is given by the formula;

$Acceleration = \frac {Force}{mass}$

Hence, Newton's 2nd Law explains why you must push harder to move a car farther because of its mass. Thus, it is important to increase the force that the engine provides and decrease the mass of the car.

6 0

3 years ago