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2 years ago

Help please i really want to pass this quiz

Physics

1 answer:

Lesechka [4]2 years ago

5 0

Answer:

It is positive and smaller in magnitude than the initial acceleration.

Explanation:

We know that acceleration is defined as the change of velocity in a given time.

We see that the time interval is equal to 30 seconds (70 - 40). In this interval we also see that the velocity increases from 245 to 250 (m/s) approximately. Therefore the acceleration is positive.

With respect to the magnitude we can say that it is smaller than at the beginning since the change of velocities is smaller with respect to the change of velocities at the beginning.

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I NEED THIS ASAP!!! A ball is thrown straight up with an initial velocity of 4.40 m/s. Assuming there is no air friction, what i

Lilit [14]

Answer:

I think it is 80m/s

Explanation:

d = ½ g t2

= ½ (10 m/s2) (4 s)2

= (5 m/s2) (16 s2)

= 80 ms

75% sure

Hope this helps!!!

5 0

3 years ago

What quantity of heat must be removed from 20g<br>of water at 0°C to change it to ice at 0°C?

seraphim [82]

The quantity of heat must be removed is 1600 cal or 1,6 kcal.

<h3>Explanation : </h3>

From the question we will know if the condition of ice is at the latent point. So, the heat level not affect the temperature, but it can change the object existence. So, for the formula we can use.

$\boxed {\bold {Q = m \times L}}$

If :

Q = heat of latent (cal or J )
m = mass of the thing (g or kg)
L = latent coefficient (cal/g or J/kg)

<h3>Steps : </h3>

If :

m = mass of water = 20 g => its easier if we use kal/g°C
L = latent coefficient = 80 cal/g

Q = ... ?

Answer :

$Q = m \times L \\ Q = 20 \times 80 = 1600 \: cal$

So, the quantity of heat must be removed is 1600 cal or 1,6 kcal.

<u>Subject : Physics </u>

<u>Subject : Physics Keyword : Heat of latent</u>

4 0

3 years ago

If two objects at different temperatures are in contact with each other, what happens to their temperatures?

miv72 [106K]

In that case, heat energy flows from the warmer object to the cooler one.
As heat flows from one to the other, the temperature of the warmer object
falls, and the temperature of the cooler object rises. When the temperatures
are equal, the flow of heat energy from one to the other stops.

6 0

2 years ago

Calculate the kinetic energy of a car of mass 1.0*10^3kg moving with a velocity of 108km/h<br>

Alekssandra [29.7K]

Answer:

450000 kg m/s

Explanation:

convert 108km/h to m/s

1km=100m

1h=(60×60)s = 3600s

108km/h= (108×1000)÷3600

=30m/s

K.E =1/2mv^2

=1/2(1×10^3)(30^2)

= 1/2 × 1000 × 900

= 450000 kg m/s

this should be your answer, hope I was able to help.

6 0

2 years ago

What voltage produces a 6-A current in a circuit thhat has a total resistance of 3 Ω ?

-Dominant- [34]

The equation we need to use is Ohm's Law

Voltage = Current * Resistance

Voltage = 6A * 3<span>Ω = 18 Volts</span>

7 0

3 years ago