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Natasha_Volkova [10]

2 years ago

8

You do 174 J of work while pulling your sister back on a swing, whose chain is 5.10 m long, until the swing makes an angle of 32

.0° with the vertical. What is your sister's mass?

1 answer:

grigory [225]2 years ago

6 0

Potential energy U = 174J = m*g*Δh

m mass
g = 9.81 m/s²
Δh = 5.1 - 5.1cos32° = 0.77

Solve for m.

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A roller coaster, traveling with an initial speed of 15 meters per second, decelerates uniformly at â7.0 meters per second2 to a

Harrizon [31]

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2 years ago

A diver explores a shallow reef off the coast of Belize. She initially swims d1 = 74.8 m north, makes a turn to the east and con

Nataly [62]

Answer:R=1607556m

θ=180degrees

Explanation:

d1=74.8m

d2=160.7km=160.7km*1000

d2=160700m

d3=80m

d4=198.1m

Using analytical method :

Rx=-(160700+75*cos(41.8))= -160755.9m

Ry= -(74.8+75sin(41.8))-198.1=73m

Magnitude, R:

R=√Rx+Ry

R=√160755.9^2+20^2=160755.916

R=160756m

Direction,θ:

θ=arctan(Rx/Ry)

θ=arctan(-73/160755.9)

θ=-7.9256*10^-6

Note that θ is in the second quadrant, so add 180

θ=180-7.9256*10^6=180degrees

8 0

2 years ago

A scientist places a strip of hot metal on top of a block of another metal with a lower melting point. The second metal quickly

gayaneshka [121]

Answer:

D:

Explanation:

Conduction because the heat energy is transferring directly from the separate metals convection involves "currents" like in a liquid or a gas. When you turn on the stove with a pot of water on the burner the water at the bottom of the pot gets heated first almost immediately this water rises and cooler water falls. Basically the water is "stirring" or shifting, exchanging the heat energy this is why water heats so evenly.

4 0

2 years ago

Juan is standing on the street. An ambulance moves toward him and then passes by. What best describes the pitch that Juan hears?

ozzi

Answer: The correct answer is "the pitch drops to a lower pitch once the ambulance passes by Juan".

Explanation:

Doppler effect is the phenomenon in which there is an increase or decrease in the frequency when there is relative motion between the source and listener.

Pitch depends on the frequency. if the frequency increases then pitch increases.

When the source and the listener are moving towards each other then there is increase in the frequency. When the source and the listener are moving away each other then there is decrease in the frequency.

In the given problem, Juan is standing on the street. An ambulance moves toward him and then passes by the pitch drops to a lower pitch once the ambulance passes by Juan.

5 0

2 years ago

Read 2 more answers

The system consists of a 20-lb disk A, 4-lb slender rod BC, and a 1-lb smooth collar C. If the disk rolls without slipping, dete

dlinn [17]

Answer:

The velocity of the collar will be 3.076 ft/s

Explanation:

Given data

weight of the disk, Wa = 20lb

weight of rod BC, Wbc = 4lb

weight of collar, Wc = 1lb

Considering the equation of equilibrium

Vb = 1.5Wbc

Wa = 1.875 Wbc

to calculate the velocity of the collar using energy conservation equation

T1 + V1 = T2 + V2

$0+4(1.5 \sin 45)+2(3 \sin 45)=\frac{1}{2}\left(\frac{1}{2}\left(\frac{20}{32.2}\right)(0.8)\right)$

=> $(1.875 W b c)+\frac{1}{2}\left(\frac{20}{32.2}\right)(1.5 W b c)+\frac{1}{2}\left(\frac{20}{32.2}\right)$

=> $(1.5 W b c) \frac{1}{2}\left\{\frac{1}{12}\left(\frac{4}{32.2}\right)(3)\right\}+\frac{1}{2}\left(\frac{1}{32.2}\right)$

=> $(2.598 W b c)+4(1.5 \sin 0)+2(3 \sin 0)$

Wbc = 1.18rad/sec

i.e.

$V _c=2.598 \times 1.18$

= 3.076 ft/ s

5 0

2 years ago