Most stars are a.brown fs b.main sequence c.white dwarfs d.pulsars

Tâm ống dẫn đặt dưới đường phân giới giữa nước và thuỷ ngân h1 = 820mm, chênh lệch chiều cao cột thuỷ ngân h2 = 880mm (Hg = 13,

gayaneshka [121]

Answer:

P = 79993.43245

Explanation:

Được -

Vị trí tâm ống dẫn dưới đường thuỷ ngân h1 = 820 mm

Chênh lệch chiều cao của cột thủy ngân h2 = 880mm

Tỷ trọng của thủy ngân = 13,5951 g / cm3

P = mật độ * gia tốc do trọng lực a * h

Thay thế các giá trị đã cho, chúng ta nhận được -

P = 13,5951 g / cm3 * 980,665 cm / s2 * (88-82) cm

P = 79993.43245

8 0

2 years ago

A model airplane with a mass of 0.741kg is tethered by a wire so that it flies in a circle 30.9 m in radius. The airplane engine

liq [111]

(a) 24.6 Nm

The torque produced by the net thrust about the center of the circle is given by:

$\tau = F r$

where

F is the magnitude of the thrust

r is the radius of the wire

Here we have

F = 0.795 N

r = 30.9 m

Therefore, the torque produced is

$\tau = (0.795 N)(30.9 m)=24.6 N m$

(b) $0.035 rad/s^2$

The equivalent of Newton's second law for a rotational motion is

$\tau = I \alpha$

where

$\tau$ is the torque

I is the moment of inertia

$\alpha$ is the angular acceleration

If we consider the airplane as a point mass with mass m = 0.741 kg, then its moment of inertia is

$I=mr^2 = (0.741 kg)(30.9 m)^2=707.5 kg m^2$

And so we can solve the previous equation to find the angular acceleration:

$\alpha = \frac{\tau}{I}=\frac{24.6 Nm}{707.5 kg m^2}=0.035 rad/s^2$

(c) $1.08 m/s^2$

The linear acceleration (tangential acceleration) in a rotational motion is given by

$a=\alpha r$

where in this problem we have

$\alpha = 0.035 rad/s^2$ is the angular acceleration

r = 30.9 m is the radius

Substituting the values, we find

$a=(0.035 rad/s^2)(30.9 m)=1.08 m/s^2$

4 0

2 years ago

Why do women typically tend to have slightly greater stability than men?

m_a_m_a [10]

Answer:

C

Explanation:

I figured it sounded more accurate

7 0

2 years ago

An object falls 210 m in 6.3 s. What was it's initial velocity? Express your answer with the correct number of significant digit

KIM [24]

Answer:

$u = 2.5 \ m/s$

Explanation:

Given data:

Height, $h = 210 \ m$

Time, $t = 6.3 \ s$

Let the initial velocity of the object be u.

From the kinematic equation,

$h = ut + \frac{1}{2}gt^{2}$

$210 = u \times 6.3 + 0.5 \times 9.80 \times (6.3)^{2}$

$\Rightarrow \ u = 2.46 \ m/s$

$u = 2.5 \ m/s$ (rounding to tenth place)

8 0

3 years ago

Why might the study of matter and energy be important

Aleksandr [31]

Answer:

The flow of matter and energy in the ecosystems is important so that the exchange necessary for them to work. In order for ecosystems to exist, there must be energy flowing and making possible the transformation of matter. Ecosystems are complex systems that exchange matter and energy with the environment and, as a result, modify it.

Explanation:

3 0

2 years ago