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3 years ago

If an object is not moving, what do we know about the forces acting on it?

Physics

2 answers:

Nat2105 [25]3 years ago

7 0

I think it should be 'They are balanced' if I'm not wrong

erik [133]3 years ago

7 0

If the object is not moving then the forces acting on it are balanced. Also if the object is moving in a straight line at a constant speed than the forces on it are also balanced.

You might be interested in

1. Which mathematical representation correctly identifies impulse?

horsena [70]

Answer:

1. B. Impulse = Force × Time

2. A. The momentum of each ball changes, and the total momentum stays the same

3. -55 kg·m/s

4. B. 3.5 kg

5. C. 6.3 m/s

Explanation:

1. The impulse is the momentum change of an object due to a force applied for a given period

2. Given that the objects collide, and the force of the 3 kg mass moving with 24 kg·m/s acts on the 1 kg mass while the total momentum is conserved;

The stationary ball of mass 1 kg begins to moves at certain velocity after collision and therefore changes momentum, while the velocity of the ball of mass 3.0 kg reduces and the total combined momentum of the two balls in the closed system remains the same

3. By the principle of conservation of linear momentum, we have;

The sum of the momentum before the collision = The sum of the momentum after collision

Given that the objects move together after the collision, the total momentum is therefore;

Total momentum = 110 kg·m/s + -65 kg·m/s + -100 kg·m/s = 110 kg·m/s - 65 kg·m/s - 100 kg·m/s = -55kg·m/s

4. Given that the final velocity of the two objects (m₁ + m₂) combined = 50 m/s

Where;

m₁ = The mass of the first object

m₂ = The mass of the second object

The total momentum of the system = 250 kg·m/s

From momentum = Mass × Velocity, we have;

Mass = Momentum/Velocity = 250 kg·m/s/(50 m/s) = 5.0 kg

The mass (m₁ + m₂) = 5.0 kg

Given that m₁ = 1.5 kg, we have;

m₂ = 5.0 kg - m₁ = 5.0 kg - 1.5 kg = 3.5 kg

The mass of the second object = 3.5 kg

5. The mass of the cue stick = 0.5 kg

The velocity of the cue stick = 2.5 m/s

The mass of the ball = 0.2 kg

The initial velocity of the ball = 0 m/s

Given that total initial momentum = Total final momentum, we have;

0.5 kg × 2.5 m/s + 0.2 kg × 0 = 0.2 kg × v + 0.5 kg × 0

0.5 kg × 2.5 m/s = 0.2 kg × v

v = (0.5 kg × 2.5 m/s)/(0.2 kg) = 6.25 m/s ≈ 6.3 m/s

3 0

4 years ago

A ray of light (f = 5.09 x 1014 Hz) is incident on the boundary between air and an unknown material X at an angle of incidence o

11Alexandr11 [23.1K]

Answer:

A) Material X is flint glass

B) Speed of light in the X material is 1.807 x $10^{8}$ m/s

C) Angle of refraction of light in medium X is $29.57^{o}$

Explanation:

Given data:

frequency of the light f = 5.09 x $10^{14}$ Hz

angle of incidence Θ $_{i}$ = $55^{o}$

index of refraction of material $n_{2}$ = 1.66

A) To find material X

Given the index of refraction is 1.66 and hence the material is the flint glass

B) To calculate the speed of light in the material.

We know that the relation between index of refraction (n), velocity of light (c = 3 x $10^{8}$ m/s) and velocity of light is given by the equation:

n = c/v

Hence,

Speed of light in the X material v = c/n

= $\frac{3 x 10^{8} }{1.66}$

= 1.807 x $10^{8}$ m/s

C) To calculate angle of refraction of light in medium X

We know that the Snell's law states that

$n_{1} sin$ Θ $_{i}$ = $n_{2} sin$ Θ $_{r}$

$n_{1}$ = incident index

$n_{2}$ = refracted index

Θ $_{i}$ = incident angle

Θ $_{r}$ = refracted angle

In given problem, $n_{1}$ = 1 since medium is air

Substituting the known values, we get

1 x $sin$ $55^{o}$ = 1.66 x $sin$ Θ $_{r}$

$sin$ Θ $_{r}$ = $sin$ $55^{o}$ /1.66

= 0.4935

Hence, angle of refraction of light in medium X Θ $_{r}$ = $sin^{-1}$ (0.4935)

= $29.57^{o}$

4 0

3 years ago

Cosmologists hypothesize and form theories to explain areas of the universe that are currently

topjm [15]

Answer:

True

Explanation:

However I do Believe that with the technological advancements we have made we could explore unexplored areas

6 0

4 years ago

svetoff [14.1K]

Answer:

9.5 seconds

Explanation:

You need to make the ending speed into meters per sec.

So it would be 120km/h = 33.33m/s

If the acceleration rate is 3.5m/s, then the final answer would equal to 9.5 seconds

Also btw rounding it up is a good idea too so 10 seconds if you round

8 0

2 years ago

Which of the following would require the<br> greatest number of calories?

disa [49]

Answer:

Heating 100 g of water from 10◦C to 50◦C

Explanation:

m₁ ΔT₁ = 2000

m₂ ΔT₂ = 300

m₃ ΔT₃ = 4000

m₄ ΔT₄ = 70

3 0

3 years ago