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ANEK
19 days ago
8

A rotating beacon is located 2 miles out in the water. Let A be the point on the shore that is closest to the beacon. As the bea

con rotates at 10 rev/min, the beam of light sweeps down the shore once each time it revolves. Assume that the shore is straight. How fast is the point where the beam hits the shore moving at an instant when the beam is lighting up a point 2 miles along the shore from the point A?
Physics
1 answer:
serg [2.5K]19 days ago
6 0

Answer:

v = 3369.2 m/s

Explanation:

The beacon is rotating at an angular speed of

f = 10 rev/min

so we have

\omega = 2\pi f

\omega = 2\pi(\frac{10}{60})

\omega = 1.047 rad/s

We know that

v = r \omega

At this point we have

r = 2 miles = 2(1609 m)

r = 3218 m

So we can conclude with

v = 3218(1.047)

v = 3369.2 m/s

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An aluminum rod is 10.0 cm long and a steel rod is 80.0 cm long when both rods are at a temperature of 15°C. Both rods have the
serg [2593]

Response:

0.9 cm

Clarification:

The following illustrates the calculation of the combined rod's length increase:

As established

Length increase = expansion of aluminum rod + expansion of steel rod

= 10cm \times 2.4e - 5\times (90-15) + 80cm\times 1.2e - 5\times (90-15)

= 0.9 cm

We simply summed the expansions of both the aluminum and steel rods to determine the overall increase in the joined rod's length, which must be factored in

4 0
3 days ago
a 75 kg man is standing at rest on ice while holding a 4kg ball. if the man throws the ball at a velocity of 3.50 m/s forward, w
Keith_Richards [2256]

Answer:

The resulting velocity for him will be 0.187 m/s in reverse direction.

Explanation:

Given:

The mass of the man is, M=75\ kg

The mass of the ball is, m=4\ kg

The initial velocity of the man is, u_m=0\ m/s(rest)

The initial velocity of the ball is, u_b=0\ m/s(rest)

The final velocity of the ball is, v_b=3.50\ m/s

The final velocity of the man is, v_m=?\ m/s

To determine this scenario, we employ the principle of momentum conservation.

This principle states that the total initial momentum equals the total final momentum.

Momentum is calculated by multiplying mass by velocity.

Initial momentum = Initial momentum of the man and the ball

Initial momentum = Mu_m+mu_b=75\times 0+4\times 0 =0\ Nm

Final momentum = Final momentum of the man and the ball

Final momentum = Mv_m+mv_b=75\times v_m+4\times 3.50 =75v_m+14

Hence, the total initial momentum equals the total final momentum

0=75v_m+14\\\\75v_m=-14\\\\v_m=\frac{-14}{75}\\\\v_m=-0.187\ m/s

The negative sign indicates that the man moves backward.

Thus, his final velocity ends up being 0.187 m/s backward.

3 0
4 days ago
When a vertical beam of light passes through a transparent medium, the rate at which its intensity I decreases is proportional t
Keith_Richards [2256]

Response:

The intensity of light 18 feet underwater is about 0.02%

Clarification:

Employing Lambert's law

Let dI / dt = kI, where k is a proportionality factor, I represents the intensity of incident light, and t indicates the thickness of the medium

Then dI / I = kdt

Taking logarithms,

ln(I) = kt + ln C

I = Ce^kt

At t=0, I=I(0) implies C=I(0)

I = I(0)e^kt

At t=3 & I=0.25I(0), we find 0.25=e^3k

Solving for k gives k = ln(0.25)/3

k = -1.386/3

k = -0.4621

I = I(0)e^(-0.4621t)

I(18) = I(0)e^(-0.4621*18)

I(18) = 0.00024413I(0)

The intensity of light 18 feet underwater is about 0.2%

3 0
19 days ago
Help asap please!! An aluminum block of mass 12.00 kg is heated from 20 C to 118 C. If the specific heat of aluminum is 913 J-1
Sav [2226]
Q = mCΔT, in which Q = energy required, m = mass of the block, C = specific heat, ΔT = temperature change.

Utilizing the values provided;

Q = 12*913*(118-20) = 1073688 J = 1073.688 kJ.

The correct option is B.
7 0
1 month ago
A sled of mass m is being pulled horizontally by a constant horizontal force of magnitude F. The coefficient of kinetic friction
kicyunya [2264]
The average velocity of the sled can be expressed with the formula vavg = s/t. Hello! The calculation for average velocity involves determining the distance traveled over time. Thus, vavg = Δx/Δt, where vavg represents average velocity, Δx is the distance traversed, and Δt is the duration of time taken. We know both the distance (s) and the time (t) required for the sled to cover that distance, which allows us to compute the average velocity using the formula vavg = s/t. Wishing you a great day!
4 0
1 day ago
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