All categories

3 years ago

Would anyone be kind enough to help me? :)

Physics

1 answer:

Travka [436]3 years ago

6 0

Answer:

The racetrack is 996.7 meters long

Explanation:

Convert 251km/h to km/s (kilometers per second)

3600 seconds in an hour, so:

251/3600 = 0.0697km/s

Convert km/s to m/s (meters per second)

1000 meters in a kilometer, so:

0.0697*1000 = 69.7m/s

Find length of racetrack:

69.7m/s*14.3s = 996.7m

If the racer travels 69.7 meters in one second and it takes 14.3 seconds to complete a lap, the racetrack is 996.7 meters long.

You might be interested in

13) Each beaker shown to the right contains iron and acid. In which beaker will the iron dissolve the fastest and why? HELP ME A

lakkis [162]

AnsweR

Explanation:

beaker B becz of increased surface area

3 0

3 years ago

The heaviest piece of equipment ever carried by plane was 12,400.05kg generator built in Germany in 1993.How far above the groun

nadezda [96]

Answer:

754.6 m

Explanation:

The GPE (Gravitational potential energy) of an object with respect to the ground is given by

$GPE = mgh$

where

m is the mass of the object

g = 9.8 m/s^2 is the acceleration due to gravity

h is the heigth above the ground

Here we have

m = 12,400.05 kg is the mass

GPE = 91,700,000.00J is the GPE

Solving the formula for h, we find the heigth:

$h=\frac{GPE}{mg}=\frac{91,700,000.00J}{(12,400.05 kg)(9.8 m/s^2)}=754.6 m$

7 0

4 years ago

A parallel-plate capacitor has plates of area 0.40 m2 and plate separation of 0.20 mm. The capacitor is connected to a 9.0 V bat

mafiozo [28]

Answer:

a) E = 4.5*10⁴ V/m

b) C= 17.7 nF

c) Q = 159. 3 nC

Explanation:

By definition, the electric field is the electrostatic force per unit charge, and since the potential difference between plates is just the work done by the field, divided by the charge, assuming a uniform electric field, if V is the potential difference between plates, and d is the separation between plates, the electric field can be expressed as follows:

$E = \frac{V}{d} = \frac{9.0V}{2*10-4m} =4.5 * 10e4 V/m (1)$

For a parallel-plate capacitor, applying the definition of capacitance as the quotient between the charge on one of the plates and the potential difference between them, and assuming a uniform surface charge density σ, we get:

$Q = \sigma* A (2)$

From (1), we know that V = E*d, but at the same time, applying Gauss'

Law at a closed surface half within the plate, half outside it , it can be

showed than E= σ/ε₀, so finally we get:

$C = \frac{Q}{V} =\frac{\sigma*A}{E*d} = \frac{\sigma*A}{\frac{\sigma}{\epsilon_{o} } d} =\frac{\epsilon_{0}*A}{d} = \frac{8.85e-12F/m*0.4m2}{2e-4m} = 17.7 nF (3)$

From (3) we can solve for Q as follows:

$Q = C* V = 17.7 nF * 9.0 V = 159.3 nC (4)$

6 0

3 years ago

An airline employee tosses two suitcases in rapid succession with a horizontal velocity of 7.2 ft/s onto a 50-lb baggage carrier

zalisa [80]

Answer:

m₁ = 70 lb

Explanation:

Here we will use the law of conservation of momentum:

m₁u₁ + m₂u₂ + m₃u₃ = m₁v₁ + m₂v₂ + m₃v₃

where,

m₁ = mass of first suitcase = ?

m₂ = mass of second suitcase = 30 lb

m₃ = mass of baggage carrier = 50 lb

u₁ = initial speed of first suitcase = 7.2 ft/s

u₂ = initial speed of second suitcase = 7.2 ft/s

u₃ = initial speed of baggage carrier = 0 ft/s

v₁ = Final speed of first suitcase = 4.8 ft/s

v₂ = Final speed of second suitcase = 4.8 ft/s

v₃ = Final speed of baggage carrier = 4.8 ft/s

because after collision all three will have same speed

Therefore,

(m₁)(7.2 ft/s) + (30 lb)(7.2 ft/s) + (50 lb)(0 ft/s) = (m₁)(4.8 ft/s) + (30 lb)(4.8 ft/s) + (50 lb)(4.8 ft/s)

(m₁)(7.2 ft/s) + (216 lb ft/s) + (0 lb ft/s) = (m₁)(4.8 ft/s) + (144 lb ft/s) + (240 lb ft/s)

(m₁)(7.2 ft/s) - (m₁)(4.8 ft/s) = 168 lb ft/s

m₁ = (168 lb ft/s)/(2.4 ft/s)

6 0

3 years ago

An electron with charge −e and mass m moves in a circular orbit of radius r around a nucleus of charge Ze, where Z is the atomic

shepuryov [24]

Answer:

$v=\sqrt{\frac{kZe^2}{mr}}$

Explanation:

The electrostatic attraction between the nucleus and the electron is given by:

$F=k\frac{(e)(Ze)}{r^2}=k\frac{Ze^2}{r^2}$ (1)

where

k is the Coulomb's constant

Ze is the charge of the nucleus

e is the charge of the electron

r is the distance between the electron and the nucleus

This electrostatic attraction provides the centripetal force that keeps the electron in circular motion, which is given by:

$F=m\frac{v^2}{r}$ (2)

where

m is the mass of the electron

v is the speed of the electron

Combining the two equations (1) and (2), we find

$k\frac{Ze^2}{r^2}=m\frac{v^2}{r}$

And solving for v, we find an expression for the speed of the electron:

$v=\sqrt{\frac{kZe^2}{mr}}$

6 0

3 years ago