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3 years ago

Rachel travels 100km in 5hrs. Find her AVERAGE SPEED. i need work shown too

Physics

1 answer:

Brilliant_brown [7]3 years ago

4 0

Answer:

20kph

Explanation:

Since she travels 100kpm in 5 hours and 100 divided by 5 is 20 she would travel 20km in one hour

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It takes a bus driver 30 minutes to pick up students from four stops. The last stop is at the corner of Green Street and Route 7

deff fn [24]

Answer:

No, the distance from the last stop to the school and the time it takes to travel that distance are required.

7 0

3 years ago

A solenoid coil with 22 turns of wire is wound tightly around another coil with 340 turns. The inner solenoid is 25.0 cm long an

LUCKY_DIMON [66]

Answer:

a) 1.34*10^-8 W

b) 1.18*10^-5 H

c) 20mV

Explanation:

a) To find the average magnetic flux trough the inner solenoid you the following formula:

$\Phi_B=BA=\mu_oNIA$

mu_o: magnetic permeability of vacuum = 4pi*10^-7 T/A

N: turns of the solenoid = 340

I: current of the inner solenoid = 0.100A

A: area of the inner solenoid = pi*r^2

r: radius of the inner solenoid = 2.00cm/2=1.00cm=10^-2m

You calculate the area and then replace the values of N, I, mu_o and A to find the magnetic flux:

$A=\pi(10^{-2}m)^2=3.141510^{-4}m^2\\\Phi_B=(4\pi*10^{-7}T/A)(340)(0.100A)(3.1415*10^{-4}m^2)=1.34*10^{-8}W\\$

the magnetic flux is 1.34*10^{-8}W

b) the mutual inductance is given by:

$M=\mu_o N_1 N_2 \frac{A_2}{l}$

N1: turns of the outer solenoid = 22

N2: turns of the inner solenoid

A_2: area of the inner solenoid

l: length of the solenoids = 25.0cm=0.25m

by replacing all these values you obtain:

$M=(4\pi*10^{-7}T/A)(340)(22)\frac{3.14*10^{-4}m^2}{0.25m}=1.18*10^{-5}H$

the mutual inductance is 1.18*10^{-5}H

c) the emf induced can be computed by using the mutual inductance and the change in the current of the inner solenoid:

$\epsilon_1=M\frac{dI_2}{dt}$

by replacing you obtain:

$\epsilon_1=(1.18*10^{-5}H)(1700A/s)=0.02V=20mV$

the emf is 20mV

7 0

3 years ago

Read 2 more answers

What is the relationship between the current passes through the

yaroslaw [1]

Increasing the number of bulbs in a series circuit decreases the brightness of the bulbs. In a series circuit, the voltage is equally distributed among all of the bulbs. Bulbs in parallel are brighter than bulbs in series. In a parallel circuit the voltage for each bulb is the same as the voltage in the circuit.

8 0

2 years ago

Coming to the bottom of a mountain, a skier moving with speed v collides with a barrier and is brought to a stop in an amount of

IRISSAK [1]

Answer:

Explanation:

Impulse of a force is measured by force x time or F X t

Impulse also equals change in momentum or

F x t = m v₂ - m v₁

The given case is as follows

in the first case

F x t = mv - o = mv

F = mv / t

in the second case

F₁ x 4 t = mv

F₁ = 1/4 x mv /t

F₁ = F / 4

option a) is correct .

iii )

In the last case

F₂ X t = m v/2 -0

F₂ = 1/2 x mv / t

= 1/2 x F

F₂ = F/2

Option e ) is correct.

8 0

3 years ago

A uniformly charged sphere has a total charge of 300uc and a radius of 8cm. Find the electric field density at A point 16cm from

s2008m [1.1K]

E = kQ 

(r + h)²

where,

k = 9 × 10^9Nm²C^-2

Q = total charge, 300uC = 300 × 10^ -6C

r = 8 × 10^ -2m

h = 16 × 10^ -2m

then,

E = 9e9 * 300e^-6 

(8e^-2 + 16e^-2)²

E = 4687500N/C

6 0

2 years ago