1. Which object has the greatest inertia?

A car moving in a straight line starts at X=0 at t=0. It passesthe point x=25.0 m with a speed of 11.0 m/s at t=3.0 s. It passes

Agata [3.3K]

Answer:

Average velocity v = 21.18 m/s

Average acceleration a = 2 m/s^2

Explanation:

Average speed equals the total distance travelled divided by the total time taken.

Average speed v = ∆x/∆t = (x2-x1)/(t2-t1)

Average acceleration equals the change in velocity divided by change in time.

Average acceleration a = ∆v/∆t = (v2-v1)/(t2-t1)

Where;

v1 and v2 are velocities at time t1 and t2 respectively.

And x1 and x2 are positions at time t1 and t2 respectively.

Given;

t1 = 3.0s

t2 = 20.0s

v1 = 11 m/s

v2 = 45 m/s

x1 = 25 m

x2 = 385 m

Substituting the values;

Average speed v = ∆x/∆t = (x2-x1)/(t2-t1)

v = (385-25)/(20-3)

v = 21.18 m/s

Average acceleration a = ∆v/∆t = (v2-v1)/(t2-t1)

a = (45-11)/(20-3)

a = 2 m/s^2

8 0

3 years ago

The world's fastest production sportscar has a top speed of 415 kmh-1(a)Convert this speed to ms-1.[ 1](b)The distance from Lond

Alex73 [517]

Answer:

(a). The speed is 115.28 m/s.

(b). The time is 94 min.

(c). The International Space Station travels 43202.400 km.

(d). Speed is scalar quantity.

Velocity is vector quantity.

Explanation:

Given that,

Top speed = 415 km/h

1 miles = 1609 m

(a). We need to calculate the speed in m/s

Using conversion of km/h to m/s

$v=415\ km/h$

$v=415\times\dfrac{5}{18}$

$v=115.28\ m/s$

(b). We need to calculate the distance from London to Edinburgh in km

Using conversion for distance

$d=403\ miles$

Distance in meter,

$d=403\times1609$

$d=648427\ m$

$d=648.427\ km$

We need to calculate the time

Using formula of time

$t=\dfrac{d}{v}$

Put the value into the formula

$t=\dfrac{648.427}{415}$

$t=1.56\ h$

$t=1\ hours 34\ min$

$t= 94\ min$

(c). Speed v' =7.66 km/s

v'=7660 m/s

In the time it takes the car to travel from London to Edinburgh,

We need to calculate the distance

Using formula of distance

$d'=v'\times t$

Put the value into the formula

$d'=7660\times94\times60$

$d'=43202400\ m$

$d'=43202.400\ km$

(d). Speed :

Speed is equal to the distance divided by time.

It is scalar quantity.

Velocity :

Velocity is equal to the displacement divided by time.

It is vector quantity.

Hence, (a). The speed is 115.28 m/s.

(b). The time is 94 min.

(c). The International Space Station travels 43202.400 km.

(d). Speed is scalar quantity.

Velocity is vector quantity.

3 0

2 years ago

What happens when two positive charges are near each other?

Westkost [7]

If two positive charges are near each other they will repel each other.

7 0

3 years ago

Consider an electron with charge −e and mass m orbiting in a circle around a hydrogen nucleus (a single proton) with charge +e.

alexandr1967 [171]

Answer:

$v=\sqrt{k\frac{e^2}{m_e r}}$ , $2.18\cdot 10^6 m/s$

Explanation:

The magnitude of the electromagnetic force between the electron and the proton in the nucleus is equal to the centripetal force:

$k\frac{(e)(e)}{r^2}=m_e \frac{v^2}{r}$

where

k is the Coulomb constant

e is the magnitude of the charge of the electron

e is the magnitude of the charge of the proton in the nucleus

r is the distance between the electron and the nucleus

v is the speed of the electron

$m_e$ is the mass of the electron

Solving for v, we find

$v=\sqrt{k\frac{e^2}{m_e r}}$

Inside an atom of hydrogen, the distance between the electron and the nucleus is approximately

$r=5.3\cdot 10^{-11}m$

while the electron mass is

$m_e = 9.11\cdot 10^{-31}kg$

and the charge is

$e=1.6\cdot 10^{-19} C$

Substituting into the formula, we find

$v=\sqrt{(9\cdot 10^9 m/s) \frac{(1.6\cdot 10^{-19} C)^2}{(9.11\cdot 10^{-31} kg)(5.3\cdot 10^{-11} m)}}=2.18\cdot 10^6 m/s$

7 0

3 years ago

Indicate whether each of the following statements is true or false. In a coal-fired power plant, chemical energy is first conver

denis23 [38]

Answer:

1. In a coal-fired power plant, chemical energy is first converted to thermal energy. TRUE.

The chemical energy in the coal is converted to thermal energy when the coal is burnt to produce steam.

2. In a coal-fired power plant, approximately 2/5 of original energy in the coal is lost to heat. FALSE.

Approximately 3/5 of the original energy is lost not 2/5 so this statement is false.

3. The molecules in cold air move faster than in hot air. FALSE.

Molecules with more heat move faster than molecules with less. Molecules in cold air therefore, will move slower than molecules in hot air.

6 0

2 years ago