A car traveling with constant speed travels 150 km in 7200s what is the speed of the car

Compare the force of air resistance and the force of gravity on an object falling at its terminal velocity.

Sholpan [36]

The viscous force on an object moving through air is proportional to its velocity.
The only forces acting on an object when falling are air resistance and its weight itself. The weight acts vertically downwards whereas air resistance acts vertically upward.
Let F be the viscous force due to air molecules, B be buoyant force due to air and W be the weight of falling object. Initially, the velocity of falling object and hence the viscous force F is zero and the object is accelerated due to force
(W-B). Because of the acceleration the velocity increases and accordingly the viscous force also increases. At a certain instant, the viscous force becomes equal to W-B. The net force then becomes zero and the object falls with constant velocity. This constant velocity is called terminal velocity.
Thus at terminal velocity, air resistance and force of gravity becomes equal.

7 0

3 years ago

A parallel-plate capacitor initially has a potential difference of 400 V and is then disconnected from the charging battery. If

Damm [24]

The capacitance of a capacitor is the ratio of the stored charge to its potential difference, i.e.

C = Q/ΔV

C is the capacitance

Q is the stored charge

ΔV is the potential difference

Rearrange the equation:

ΔV = Q/C

We also know the capacitance of a parallel-plate capacitor is given by:

C = κε₀A/d

C is the capacitance

κ is the capacitor's dielectric constant

ε₀ is the electric constant

A is the area of the plates

d is the plate separation

If we substitute C:

ΔV = Qd/(κε₀A)

We assume the stored charge and the area of the plates don't change. Then if we double the plate spacing, i.e. we double the value of d, then the potential difference ΔV is also doubled.

5 0

2 years ago

A marble rolls 269cm across the floor with a constant speed of in 44.1cm/s.

Marrrta [24]

Answer:

t = 6.09 seconds

Explanation:

Given that,

Speed, v = 44.1 cm/s

Distance, d = 269 cm

We need to find the time interval of the marble. Speed is distance per unit time.

$v=\dfrac{d}{t}\\\\\implies t=\dfrac{d}{v}\\\\t=\dfrac{269\ \text{cm}}{44.1\ \text{cm/s}}\\\\t=6.09\ s$

Hence, the time interval of the marble is 6.09 seconds.

6 0

3 years ago

This diagram shows particles that make up an atom. Which label BEST completes the diagram ?

worty [1.4K]

Answer: option A. strong nuclear force.

Explanation:

The diagram shows the subatomic particles inside the nucelous: protons and neutrons.

As you know, the protons are positively charged partilces inside the nucleous.

Being those particles charged with the same kind of charge they experiment electrostatic repulsion. So, how do you explain that they can stand together in such small space as it is the nucleous?

The responsible of keeping the subatomic particles together is the so called strong nuclear force.

Strong nuclear force or simply strong force is one of the four fundamental interactions or forces: i) gravitational, ii) electromagnetic, iii) weak nuclear force, and iv) strong nuclear force.

Strong nuclear force is the strongest force of nature and acts only in short distances as those inside the nucleous and is responsible for both the atraction among quarks and the atraction among protons to bind them together inside the atomic nucleous.

8 0

3 years ago

A girl (mass M) standing on the edge of a frictionless merry-go-round (radius R, rotational inertia I) that is not moving. She t

vladimir1956 [14]

a) $\omega=\frac{-mvR}{I+MR^2}$