Modern scientists use a version of the metric system called

a charge of 4.5 times 10 to the negative 5 C is placed in an electric field with a strength of 2.0 times 10 to the 4 N over C. i

Rama09 [41]

Answer:

C

Explanation:

7 0

3 years ago

Andy is waiting at the signal. As soon as the light turns green, he accelerates his car at a uniform rate of 8.00 meters/second2

Tatiana [17]

You can reason it out like this:

-- The car starts from rest, and goes 8 m/s faster every second.

-- After 30 seconds, it's going (30 x 8) = 240 m/s.

-- Its average speed during that 30 sec is (1/2) (0 + 240) = 120 m/s

-- Distance covered in 30 sec at an average speed of 120 m/s

   = 3,600 meters .
___________________________________

The formula that has all of this in it is the formula for
distance covered when accelerating from rest:

   Distance = (1/2) · (acceleration) · (time)²

   = (1/2) · (8 m/s²)    · (30 sec)²

   = (4 m/s²) · (900 sec²)

   = 3600 meters.

_________________________________

When you translate these numbers into units for which
we have an intuitive feeling, you find that this problem is
quite bogus, but entertaining nonetheless.

When the light turns green, Andy mashes the pedal to the metal
and covers almost 2.25 miles in 30 seconds.

How does he do that ?

By accelerating at 8 m/s². That's about 0.82 G !

He does zero to 60 mph in 3.4 seconds, and at the end
of the 30 seconds, he's moving at 534 mph !

He doesn't need to worry about getting a speeding ticket.
Police cars and helicopters can't go that fast, and his local
police department doesn't have a jet fighter plane to chase
cars with.

3 0

4 years ago

when a temparature of a coin is 75°C, the coin's diameter increases. if the original diameter of a coin is 1.8*10^-2 m and its c

andrey2020 [161]

Answer:

ΔD = 2.29 10⁻⁵ m

Explanation:

This is a problem of thermal expansion, if the temperature changes are not very large we can use the relation

ΔA = 2α A ΔT

the area is

A = π r² = π D² / 4

we substitute

ΔA = 2α π D² ΔT/4

as they do not indicate the initial temperature, we assume that ΔT = 75ºC

α = 1.7 10⁻⁵ ºC⁻¹

we calculate

ΔA = 2 1.7 10⁻⁵ pi (1.8 10⁻²) ² 75/4

ΔA = 6.49 10⁻⁷ m²

by definition

ΔA = A_f- A₀

A_f = ΔA + A₀

A_f = 6.49 10⁻⁷ + π (1.8 10⁻²)² / 4

A_f = 6.49 10⁻⁷ + 2.544 10⁻⁴

A_f = 2,551 10⁻⁴ m²

the area is

A_f = π D_f² / 4

A_f = $\sqrt{4 A_f /\pi }$

D_f = $\sqrt{4 \ 2.551 10^{-4} /\pi }$

D_f = 1.80229 10⁻² m

the change in diameter is

ΔD = D_f - D₀

ΔD = (1.80229 - 1.8) 10⁻² m

ΔD = 0.00229 10⁻² m

ΔD = 2.29 10⁻⁵ m

5 0

3 years ago

A Carnot engine operates with an efficiency of 26.0% when the temperature of its cold reservoir is 281 K. Assuming that the temp

VLD [36.1K]

Answer:

The temperature of cold reservoir should be 246.818 K for efficiency of 35%

Explanation:

In first case we have given efficiency of Carnot engine = 26 % = 0.26

Temperature of cold reservoir $T_L=281K$

We know that efficiency of Carnot engine is given by

$\eta =1-\frac{T_L}{T_H}$

$0.26 =1-\frac{281}{T_H}$

$T_H=379.72K$

For second Carnot engine efficiency is given as 35% = 0.35

And temperature of hot reservoir is same so $T_H=379.72K$

So $0.35=1-\frac{T_L}{379.72}$

$T_L=246.818K$

So the temperature of cold reservoir should be 246.818 K for efficiency of 35%

4 0

4 years ago

Which is a negatively charged particle in an atom?

koban [17]

Answer:

electrons

Explanation:

electrons are negatively charged particles in an atom

3 0

3 years ago