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3 years ago

4. An object is moving with an initial velocity of 9 m/s. It accelerates at a rate of 1.5

Physics

1 answer:

Mazyrski [523]3 years ago

7 0

Answer:

11.87 ms⁻¹

Explanation:

You can use the kinematic equation

v² = u² + 2as

Where v = final velocity

u = initial velocity

a = acceleration

s = displacement

v² = 9² + 2×1.5×20

So you get v = 11.87 ms⁻¹

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Two forces,one of 12 N and another of 24 N,act on a body in such a way that they make an angle of 90degree with each other.Find

jok3333 [9.3K]

Answer:

26.83 N.

Explanation:

If the angle between two vector is 90°, to get the resultant, we use Pythagoras theorem.

a² = b²+c²......................... Equation 1

Where a = R = Resultant, b = 12 N, c = 24 N.

Substitute these values into equation 1

R² = 12²+24²

R² = 144+576

R² = 720

√R² = √720

R = 26.83 N.

Hence, the result of the two force is 26.83 N.

4 0

3 years ago

What's the diameter of a dish antenna that will receive 10−20W of power from Voyager at this time? Assume that the radio transmi

Murrr4er [49]

Complete Question:

The Voyager 1 spacecraft is now beyond the outer reaches of our solar system, but earthbound scientists still receive data from the spacecraft s 20-W radio transmitter. Voyager is expected to continue transmitting until about 2025, when it will be some 25 billion km from Earth.

What s the diameter of a dish antenna that will receive 10−20W of power from Voyager at this time? Assume that the radio transmitter on Voyager transmits equally in all directions(isotropically). In fact, the antenna on Voyager focuses the signal in a beam aimed at the earth, so this problem over-estimates the size of the receiving dish needed.

Answer:

d = 2,236 m.

Explanation:

The received power on Earth, can be calculated as the product of the intensity (or power density) times the area that intercepts the power radiated.

As we assume that the transmitter antenna is ominidirectional, power is spreading out over a sphere with a radius equal to the distance to the source.

So, we can get the power density as follows:

I = P /A = P / 4*π*r², where P = 20 W, and r= 25 billion km = 25*10¹² m.

⇒ I = 20 W / 4*π* (25*10¹²)² m²

The received power, is just the product of this value times the area of the receiver antenna, which we assumed be a circle of diameter d:

Pr = I. Ar =( 20W / 4*π*(25*10¹²)² m²) * π * (d²/4) = 10⁻²⁰ W

Simplifying common terms, we can solve for d:

d= √(16*(25)²*10⁴/20) = 2,236 m.

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3 years ago

An intravenous (IV) system is supplying saline solution to a patient at the rate of 0.06 cm3/s through a needle of radius 0.2 mm

horsena [70]

Answer: