1. True or False: Most things in motion are accelerating, few things in real life move at a constant speed.

You push really hard against a round rock, but you cannot make it roll. Which statement best explains why you cannot move the ro

cluponka [151]

Answer:

b

Explanation:

a Gravity pulls the rock toward the center of Earth.

b The forces between you and the rock are balanced.

c The force of your push is greater than the opposing force.

d There is no friction to help you move the object.

The correct answer would be that <u>the forces between you and the rock are balanced.</u>

<em>In order to get the rock rolling, both the frictional force between the rock and the surface on which it stands as well as the gravitational force acting on its mass must be exceeded. If the applied force balances these forces or falls short, the rock will not move.</em>

The correct option is b.

8 0

2 years ago

2) [25 pts] The bob of mass m=5 kg shown in the figure is being held by a force F. If the angle is 0⃗

Colt1911 [192]

Complete Question

The complete question is shown on the first uploaded image

Answer:

a

The tension is $T = 48.255 \ N$

b

The time taken is $t = 0.226 \ s$

c

The position for maximum velocity is

S = 0

d

The maximum velocity is $V_{max} =0.384 \ m/s$

Explanation:

The free body for this question is shown on the second uploaded image

From the question we are told that

The mass of the bob is $m_b = 5 \ kg$

The angle is $\theta = 10^o$

The length of the string is $L = 0.5 \ m$

The tension on the string is mathematically represented as

$T = mg cos \theta$

substituting values

$T = 5 * 9.8 cos(10)$

$T = 48.255 \ N$

The motion of the bob is mathematically represented as

$S = A sin (w t + \frac{\pi }{2} )$

=> $S = A sin (wt)$

Where $w$ is the angular speed

and $\frac{\pi}{2}$ is the phase change

At initial position S = 0

So $wt = cos^{-1} (0)$

$wt = 1$

Generally $w$ can be mathematically represented as

$w = \frac{2 \pi }{T}$

Where T is the period of oscillation which i mathematically represented as

$T = 2 \pi \sqrt{\frac{L}{g} }$

So

$t = \frac{1}{w}$

$t = \frac{T}{2 \pi}$

$t = \sqrt{\frac{L}{g} }$

substituting values

$t = \sqrt{\frac{0.5}{9.8} }$

$t = 0.226 \ s$

Looking at the equation

$wt = 1$

We see that maximum velocity of the bob will be at S = 0

i. e $w = \frac{1}{t}$

The maximum velocity is mathematically represented as

$V_{max} = w A$

Where A is the amplitude which is mathematically represented as

$A = L sin \theta$

So

$V_{max} = \frac{2 \pi }{T } L sin \theta$

$V_{max} = \frac{2 \pi }{2 \pi } \sqrt{\frac{g}{L} } L sin \theta$ Recall $T = 2 \pi \sqrt{\frac{L}{g} }$

$V_{max} = \sqrt{gL} sin \theta$

substituting values

$V_{max} = \sqrt{9.8 * 0.5 } sin (10)$

$V_{max} =0.384 \ m/s$

6 0

2 years ago

What is happening in the picture?

Veseljchak [2.6K]

The gravity is pushing rhe boat down

3 0

3 years ago

Read 2 more answers

Guyz... Its my first question in this app... Pls do answer

Basile [38]

Answer:

1.414

Explanation:

Snell's law states:

n₁ sin θ₁ = n₂ sin θ₂

where n is the index of refraction and θ is the angle of incidence (relative to the normal).

The index of refraction of air is approximately 1. So:

1 sin 45° = n sin 30°

n = sin 45° / sin 30°

n = 1.414

Round as needed.

6 0

3 years ago

Jonas sees this symbol in a circuit diagram.

Alenkinab [10]

The circuit component the symbol represents is: C) Battery

3 0

3 years ago

Read 2 more answers