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3 years ago

Which of the below statements are true?

Physics

1 answer:

andrezito [222]3 years ago

4 0

Answer:

Explanation:

Displacement is the distance from the start point to the endpoint, displacement disregard the path taken or the amount traveled.

if you start at point A, then go to point B, and back to point A, the displacement is zero because you started and ended at the same point.

for this question, pretend you started at point A, went east 20 km to point B, and then west 8 km to point C, your displacement is 12 km. 12 km is the distance between point A and point C.

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Select each correct answer. If an object is moving, the amount of kinetic energy it has directly depends upon which of the follo

Jobisdone [24]

If an object is moving, the amount of kinetic energy it has directly depends upon which of the following factors?
- the object's mass
- the object's velocity

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3 years ago

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A student drops a 0.4kg ball from a height a of 49m above the ground. Neglect drag. Answer each of the following questions about

Elan Coil [88]

• The only force acting on the ball, and thus the net force, is due to its own weight, with magnitude

w = m g = (0.4 kg) (9.8 m/s²) ≈ 3.9 N

pointing downward.

• The ball is in free fall, so its acceleration is g = 9.8 m/s² (also pointing downward).

• The ball is dropped from a height of 49 m, so its height y at time t is

y = 49 m - 1/2 g t ²

Set y = 0 and solve for t :

0 = 49 m - 1/2 g t ²

t ² = (98 m) / g

t = √((98 m) / g) = √(10) s ≈ 3.2 s

• The ball's velocity v at time t is

v = - g t

so that at the time found previously, the ball will have attained a velocity of

v = - g (3.2 s) ≈ -31 m/s

and thus a speed of about 31 m/s.

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3 years ago

How can a person detect infrared rays without an instrument?

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The dimensions of a room are 16.40 m long, 4.5 m wide and 3.26 m high. What is the volume of the room in cubic meters? Express y

anyanavicka [17]

Answer:

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3 years ago

The perihelion of the comet TOTAS is 1.69 AU and the aphelion is 4.40 AU. Given that its speed at perihelion is 28 km/s, what is

dybincka [34]

Answer:

The speed at the aphelion is 10.75 km/s.

Explanation:

The angular momentum is defined as:

$L = mrv$ (1)

Since there is no torque acting on the system, it can be expressed in the following way:

$t = \frac{\Delta L}{\Delta t}$

$t \Delta t = \Delta L$

$\Delta L = 0$

$L_{a} - L_{p} = 0$

$L_{a} = L_{p}$ (2)

Replacing equation 1 in equation 2 it is gotten:

$mr_{a}v_{a} =mr_{p}v_{p}$ (3)

Where m is the mass of the comet, $r_{a}$ is the orbital radius at the aphelion, $v_{a}$ is the speed at the aphelion, $r_{p}$ is the orbital radius at the perihelion and $v_{p}$ is the speed at the perihelion.

From equation 3 v_{a} will be isolated:

$v_{a} = \frac{mr_{p}v_{p}}{mr_{a}}$

$v_{a} = \frac{r_{p}v_{p}}{r_{a}}$ (4)

Before replacing all the values in equation 4 it is necessary to express the orbital radius for the perihelion and the aphelion from AU (astronomical units) to meters, and then from meters to kilometers:

$r_{p} = 1.69 AU x \frac{1.496x10^{11} m}{1 AU}$ ⇒ $2.528x10^{11} m$