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borishaifa [10]
3 years ago
13

a car travel uniformly speed of 30 km/h for 30 minutes and then at uniform speed of 60km/h for next 30min calculate the average

speed of car​
Physics
1 answer:
algol133 years ago
3 0

Explanation:

i hope this will help you

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A. If you set a cannonball to 1500 m/s, what happens? Explain why you think it moves this way.
creativ13 [48]

Answer:

I beleive it would shoot very far up into the sky

Explanation:

7 0
3 years ago
Read 2 more answers
Suppose the entire population of the world gathers in ONE spot and everyone jumps at the sound of a prearranged signal. While ev
puteri [66]

Answer:

(b) Yes, the earth gains momentum but the change in momentum of the earth is much lesser compared to that of everyone in the air. The resistance to motion (inertia of the earth), which is a function of its mass is so great that the earth's acceleration is small in the given time frame.

Explanation:

From Newton's second law which can be stated mathematically as

F = m(v-u)/t = ma.

By Newton's law of gravitation, there is a force between the earth and everyone in the air. This force is responsible for the change in momentum of everyone in the air and this force gives them an acceleration equal to g = 9.80m/s². By Newton's law of gravitation and Newton's third law of motion, this force is also equal to the force exerted by everyone on the earth.

For this to be true,

F = M (everyone) ×a (everyone) = M(earth) × a (earth).

And

a (earth) = {M (everyone) ×a (everyone) }/M (earth)

Then

a (earth) must be lesser than a (everyone) since M(earth) >> M(everyone).

a = change in momentum/ time

Therefore the earth will have a much lesser change in momentum which is the reason we won't notice the earth's movement.

Thank you for reading.

6 0
3 years ago
What is the unit for magnitudes in astronomy?
Sonja [21]
The unit is light years or Ly
3 0
3 years ago
Yvette hangs a 2.4kg bird feeder in the middle of a rope tied between two trees, the feeder creates a
kicyunya [14]

Answer:

a) 0.049 m

b) Yes, increase

Explanation:

Draw a free body diagram.

In the y direction, there are three forces acting on the feeder.  Two vertical components of the tension forces in each rope pulling up, and weight force pulling down.

Apply Newton's second law to the feeder in the y direction.

∑F = ma

2Ty − mg = 0

Ty = mg/2

Let's say the distance the rope sags is d.  The trees are 4m apart, so the feeder is 2m horizontally from either tree.  Using Pythagorean theorem, we can find the length of the rope on either side:

L² = 2² + d²

L = √(4 + d²)

Using similar triangles, we can write a proportion using the forces and distances.

Ty / T = d / L

Substitute:

(mg/2) / T = d / √(4 + d²)

Solve for d:

Td = mg/2 √(4 + d²)

T² d² = (mg/2)² (4 + d²)

T² d² = (mg)² + (mg/2)² d²

(T² − (mg/2)²) d² = (mg)²

d² = (mg)² / (T² − (mg/2)²)

d = mg / √(T² − (mg/2)²)

Given m = 2.4 kg and T = 480 N:

d = (2.4) (9.8) / √(480² − (2.4×9.8/2)²)

d = 0.049 m

b) If a bird lands on a feeder, this will increase the tension in the rope to support the bird's weight.

8 0
3 years ago
g A wheel of diameter 8.0 cm has a cord of length 6.0 m wound around its periphery. Starting from rest, the wheel is given a con
sveticcg [70]

To solve this problem it is necessary to apply the equations related to the description of the tangential and angular movement.

The displacement where the speed and acceleration is related is given by the equation:

x = v_0t+\frac{1}{2}at^2

Where

v_0 = Initial velocity (0 because start from rest)

t = time

a = Acceleration

We have angular acceleration but not tangential acceleration. Tangential acceleration can be obtained through the relationship

a = r\alpha \rightarrow r = \frac{diameter}{2}

a = \frac{0.08}{2}(3)

a = 0.12m/s^2

And we have also that the displacement is

x = 6m

Now replacing,

x = v_0t+\frac{1}{2}at^2

6 = 0*t+\frac{1}{2}(0.12)t^2

6 = \frac{1}{2}(0.12)t^2

t = 10s

Therefore will take the cord to unwind around 10s

7 0
3 years ago
Read 2 more answers
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