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3 years ago

Which of the following is an example of a properly written testable hypothesis? *

Physics

1 answer:

sveta [45]3 years ago

3 0

Answer:

D. if it is dark, then an owl will find a mouse by the sound the mouse makes

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" When the apple falls,does the apple also attract the earth?

Gre4nikov [31]

Answer:

yes

Explanation:

masses attract each other

with a teeny-tiny force

8 0

2 years ago

The flywheel of a steam engine runs with a constant angular velocity of 190 rev/min. When steam is shut off, the friction of the

Ivanshal [37]

Answer:

(a) $\alpha = - 1.32\ rev/m^{2}$

(b) $\theta = 13674\ rev$

(d) $a = 22.458\ m/s^{2}$

Solution:

As per the question:

Angular velocity, $\omega = 190\ rev/min$

Time taken by the wheel to stop, t = 2.4 h = $2.4\times 60 = 144\ min$

Distance from the axis, R = 38 cm = 0.38 m

Now,

(a) To calculate the constant angular velocity, suing Kinematic eqn for rotational motion:

$\omega' = \omega + \alpha t$

$omega'$ = final angular velocity

$\omega$ = initial angular velocity

$\alpha$ = angular acceleration

Now,

$0 = 190 + \alpha \times 144$

$\alpha = - 1.32\ rev/m^{2}$

Now,

(b) The no. of revolutions is given by:

$\omega'^{2} = \omega^{2} + 2\alpha \theta$

$0 = 190^{2} + 2\times (- 1.32) \theta$

$\theta = 13674\ rev$

(c) Tangential component does not depend on instantaneous angular velocity but depends on radius and angular acceleration:

$\alpha_{tan} = 0.38\times 1.32\times \frac{2\pi}{3600} = 8.75\times 10^{- 4}\ m/s^{2}$

(d) The radial acceleration is given by:

$\alpha_{R} = R\omega^{2} = 0.32(80\times \frac{2\pi}{60})^{2} = 22.45\ rad/s$

Linear acceleration is given by:

$a = \sqrt{\alpha_{R}^{2} + \alpha_{tan}^{2}}$

$a = \sqrt{22.45^{2} + (8.75\times 10^{- 4})^{2}} = 22.458\ m/s^{2}$

5 0

2 years ago

An alpha particle (α), which is the same as a helium-4 nucleus, is momentarily at rest in a region of space occupied by an elect

alexgriva [62]

Answer:

Explanation:

Kinetic energy gained by alpha particle

= charge x potential difference

1/2 mv² = 3.2 x 10⁻¹⁹ x 3.45 x 10⁻³

.5 x 6.68 x 10⁻²⁷ V² = 11.04 x 10⁻²²

V² = 3.3 x 10⁵

V = 5.74 x 100

= 574 m / s

Mechanical energy is conserved in respect of A , C and D .

Part B

B , C, are unknown .

8 0

3 years ago

A worker pushes horizontally on a 34 kg crate with a force of magnitude 110 n . the coefficient of static friction between the c

Vadim26 [7]

<span>Static frictional force = 126.91 N
1st worker force = 110 N
2nd worker = 126.91 – 110 = 16.91 N</span>electron1 <span>· 7 years ago.</span>

4 0

2 years ago

Identify which of the following objects has the most inertia: 3 g gumball; 2 kg tennis ball; 2 g ping

goldenfox [79]

5 kg basketball. Inertia is related to the mass of the object.

6 0

3 years ago