Physics. I need help

satela [25.4K]

Answer:

Changes in the object's momentum (answer D)

Explanation:

A net force will cause an object to change its velocity, and that will affect the object's momentum, which is defined by the product of the object's mass times its velocity.

So, select the last option (D) in the given list.

8 0

3 years ago

If the moon phase is seen as a waxing crescent moon in london, what phase of the moon would be seen in new york if it's viewed a

Murljashka [212]

Lunar phase is the same wherever on Earth you observe
<span>Last (third) quarter rises at midnight, sets at noon. </span>
<span>First quarter rises at noon, sets at midnight</span>

4 0

3 years ago

A rock climber stands on top of a 50 m -high cliff overhanging a pool of water. He throws two stones vertically downward 1.0 s a

bagirrra123 [75]

<h2><em>Answer: b) What was the initial speed of the second stone?</em></h2>

Explanation:

3 0

3 years ago

What are (a) the lowest frequency, (b) the second lowest frequency, and (c) the third lowest frequency for standing waves on a w

Delvig [45]

(a) The lowest frequency (called fundamental frequency) of a wire stretched under a tension T is given by
$f_1 = \frac{1}{2L} \sqrt{ \frac{T}{m/L} }$
where
L is the wire length
T is the tension
m is the wire mass

In our problem, L=10.9 m, m=55.8 g=0.0558 kg and T=253 N, therefore the fundamental frequency of the wire is
$T= \frac{1}{2L} \sqrt{ \frac{T}{m/L} }= \frac{1}{2 \cdot 10.9 m} \sqrt{ \frac{253 N}{0.0558 kg/10.9 m} }= 10.2 Hz$

b) The frequency of the nth-harmonic for a standing wave in a wire is given by
$f_n = n f_1$
where n is the order of the harmonic and f1 is the fundamental frequency. If we use n=2, we find the second lowest frequency of the wire:
$f_2 = 2 f_1 = 2 \cdot 10.2 Hz=20.4 Hz$

c) Similarly, the third lowest frequency (third harmonic) is given by
$f_3 = 3 f_1 = 3 \cdot 10.2 Hz = 30.6 Hz$

8 0

3 years ago

5) Consider pushing a 50.0 kg box through a 5.00 m displacement on both a flat surface and up a

Svetach [21]

a) The work done by the gravitational force on the flat surface is zero

b) The work done by the gravitational force on the ramp is -634 J

c) The work done by the applied force on the flat surface is 500 J

d) The work done by the applied force on up along the ramp is 500 J

Explanation:

a)

The work done by a force is given by the equation

$W=Fdcos \theta$

where

F is the magnitude of the force

d is the dispalcement of the object

$\theta$ is the angle between the direction of the force and of the displacement

In this problem, we want to calculate the work done by the gravitational force as the box is pushed across the flat ground.

We immediately notice that the gravitational force acts downward, while the displacement is horizontal: therefore, the angle between force and displacement is $90^{\circ}$ ; this means that $cos 90^{\circ}=0$ , and therefore, the work done is zero:

$W=0$

b)

In this case, the box is pushed along the ramp. We have:

$F=mg=(50.0)(9.8)=490 N$ is the magnitude of the force of gravity, where

m = 50.0 kg is the mass of the box

$g=9.8 m/s^2$ is the acceleration of gravity

d = 5.00 m is the displacement of the box along the ramp

The ramp is inclined to the horizontal by $15.0^{\circ}$ , therefore the angle between the force of gravity and the displacement of the box (moving up along the ramp) is: