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3 years ago

As the ambulance got closer, Marge noticed that the pitch of the siren got higher. This happened because

Physics

2 answers:

disa [49]3 years ago

7 0

Answer:

The correct choice is

A) the sound waves were pushed closer together.

Explanation:

As the ambulance gets closer, the distance between the ambulance and marge decreases and so does the wavelength of the siren observed by marge. As the wavelength decrease and speed remains the same for the siren, the frequency of the siren increases because wavelength, frequency and speed are related as

Frequency = Speed/wavelength

Clearly, the frequency is inversely related to wavelength.

AfilCa [17]3 years ago

6 0

A) the sound waves were pushed closer together

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A pitcher throws a 0.144-kg baseball toward the batter so that it crosses home plate horizontally and has a speed of 42 m/s just

Solnce55 [7]

(a) 12.8 kg m/s

The impulse delivered by the bat on the baseball is equal to the change in momentum of the baseball:

$I=\Delta p = m(v-u)$

where we have

m = 0.144 kg is the mass of the ball

v = -47 m/s is the final velocity of the ball

u = 42 m/s is the initial velocity of the ball

Substituting into the equation, we find

$I=(0.144 kg)(-47 m/s-(42 m/s))=-12.8 kg m/s$

And since we are interested in the magnitude only,

$I=12.8 kg m/s$

(b) 2.78 kN

The impulse exerted on the ball is also equal to the product between the average force and the contact time:

$I=F\Delta t$

where

F is the average force exerted on the ball

$\Delta t=0.0046 s$ is the contact time

Solving the formula for F, we find

$F=\frac{I}{\Delta t}=\frac{12.8 kg m/s}{0.0046 s}=2783 N = 2.78 kN$

(c) The force exerted on the ball is much larger (1988 times more) than the weigth of the ball

The weight of the ball is given by

$W=mg$

where

m = 0.144 kg is the mass of the ball

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

Solving the equation for W, we find

$W=(0.144 kg)(9.8 m/s^2)=1.4 N$

So as we see, the force exerted on the ball (2783 N) is almost 2000 times larger than the weight of the ball (1.4 N):

$\frac{F}{W}=\frac{2783 N}{1.4 N}=1988$

8 0

3 years ago

Two samples of water are mixed together.

horrorfan [7]

Let the cold water go up x degrees.

Let the hot water go down 100 - x degrees.

The formula for heat exchange is m*c*delta t

Givens

Ice

deltat = x

m = 0.50 kg

c = 4.18

Hot water

deltat = 100 - x

m = 1.5 kg

c = 4.18

Formula

The heat up = heat down

0.50 * c * x = 1.5 * c * (100 - x) Divide both sides by c

Solution

0.50 *x = 1.5*(100 - x) Remove the brackets.

0.5x = 150 - 1.5x Add 1.5x to both sides.

0.5x + 1.5x = 150 - 1.5x + 1.5x Combine like terms

2x = 150 Divide by 2

x = 75

Answer

6 0

3 years ago

If the earth were twice the distance from the sun that it is now, the gravitational force exerted on it by the sun would be: a)

devlian [24]

Answer:

a) 1/4 what it is now

Explanation:

As we know that force of gravitation between two planets at some distance "r" from each other is given as

$F_g = \frac{Gm_1m_2}{r^2}$

now since we know that if the distance between Earth and Sun is changed

So the force of gravity will be given as

$\frac{F_g'}{F_g} = \frac{r_1^2}{r_2^2}$

now we know that the distance between sun and earth is changed to twice the initial distance between them

so we have

$r_2 = 2r_1$

so new gravitational force between sun and earth is given as

$F_g' = \frac{r_1^2}{(2r_1)^2}F_g$

$F_g' = \frac{1}{4}F_g$

4 0

3 years ago

Choose the letter for the acceleration of the ball during the upward motion after it is released. a) The acceleration is in the

lianna [129]

Answer:

Option (a)

Explanation:

If a body is thrown upwards, it's velocity goes on decreasing with constant rate. It is because an acceleration is acting on the body which is equal to acceleration due to gravity and acting downwards. The value of acceleration due to gravity is constant and always acting downwards.

8 0

4 years ago

Ozone, O3 methane, CH4 oxygen gas, O2 Are classified as

erma4kov [3.2K]

I would think compounds.

5 0

3 years ago

Read 2 more answers