All categories

2 years ago

A 6kg rock rolls down a hill with a momentum of 12kg m/s . Work out the velocity of the rock

Physics

2 answers:

Feliz [49]2 years ago

8 0

Answer:

Momentum= mass x velocity

So velocity= Momentum/mass= 12/6= 2m/s

Nat2105 [25]2 years ago

7 0

Answer:

if you need to get the work=force×displacement or if you need the velocity=displacement÷time taken

You might be interested in

Newton's third law states that for every action force there is an equal and opposite reaction force. An idiot in your class says

Otrada [13]

A. Because the third laws say that for every action force the is an equal and opposite reaction force

4 0

3 years ago

Read 2 more answers

Object's velocity change

marshall27 [118]

the definition of acceleration in kinematics, allows to find that the correct answer is:

2. speed up ( acceleration)

The kinematics study the movement of the body, the acceleration is defined as the change of the speed by the time in the interval

a = Δv / t

Where the bold letters indicate vectors, a is the acceleration, v the velocity and t the time

Analyzing this expression we see that for there to be a change in velocity, there must be an acceleration of the body.

Let's analyze the different claims

1. True. If it is stopped and you start to move there is an acceleration, therefore there is a change in speed, but after you are moving the acceleration becomes zero and there is no change in speed

2. True. Whenever there is acceleration there is a change in speed

3. False. Moving slowly does not change the acceleration, therefore there is no change in speed

4. True. If you are moving and you stop at this moment there is an acceleration, therefore there is a change in speed, but after being stopped the acceleration is zero and there is no change in speed

5. False. If you change the direction at the instant of change there is an acceleration but after you go in the opposite direction there is not acceleration therefore there is no change in speed.

In conclusion using the definition of acceleration in kinematics, we can find the answer the condition for a change in velocity, the correct statement is:

2. speed up ( acceleration)

Learn more here: brainly.com/question/5063616

3 0

2 years ago

I am really struggling with this question because I can't find anything on aphelion and perihelion, it's not a topic we went ove

Hoochie [10]

I have a strange hunch that there's some more material or previous work
that goes along with this question, which you haven't included here.

I can't easily find the dates of Mercury's extremes, but here's some of the
other data you're looking for:

Distance at Aphelion (point in it's orbit that's farthest from the sun):
69,816,900 km
0. 466 697 AU

 Distance at Perihelion (point in it's orbit that's closest to the sun):
46,001,200 km
0.307 499 AU 

Perihelion and aphelion are always directly opposite each other in
the orbit, so the time between them is 1/2 of the orbital period.

Mercury's Orbital period = 87.9691 Earth days

1/2 (50%) of that is 43.9845 Earth days

The average of the aphelion and perihelion distances is

1/2 ( 69,816,900 + 46,001,200 ) = 57,909,050 km
or
1/2 ( 0.466697 + 0.307499) = 0.387 098 AU

This also happens to be 1/2 of the major axis of the elliptical orbit.

3 0

3 years ago

A satellite orbits earth with a mean altitude of 361 km. If the orbit is circular, what are the satellite's time period and spee

Advocard [28]

Answer:

v = 7.69 x 10³ m/s = 7690 m/s

T = 5500 s = 91.67 min = 1.53 h

Explanation:

In order for the satellite to orbit the earth, the force of gravitation on satellite must be equal to the centripetal force acting on it:

$F_{gravitation}= F_{centripetal}\\\\\frac{GM_{s} M_{E}}{r^2} = \frac{M_{s} v^2}{r}\\\\\frac{GM_{E}}{r} = v^2\\\\v = \sqrt{\frac{GM_{E}}{r} } \\\\$

where,

G = Universal Gravitational Constant = 6.67 x 10⁻¹¹ N.m²/kg²

Me = Mass of Earth = 5.97 x 10²⁴ kg

r = distance between the center of Earth and Satellite = Radius of Earth + Altitude = 6.371 x 10⁶ m + 0.361 x 10⁶ m = 6.732 x 10⁶ m

v = orbital speed = ?

Therefore,

$v = \sqrt{\frac{(6.67 x 10^{-11}N.m^2/kg^2)(5.97 x 10^{24} kg)}{6.732 x 10^6 m} }\\\\$

v = 7.69 x 10³ m/s

For time period satellite completes one revolution around the earth. It means that the distance covered by satellite is equal to circumference of circle at the given altitude.

So, its orbital speed can be given as:

$v = \frac{Circumference of Circle at Given Altitude}{T}\\\\v = \frac{2\pi r}{T}\\\\$