Which of the following items is an example of a symbol Bernice bobs her hair

A bike accelerates uniformly from rest to a speed of 7.10 m/s over a distance of 35.4m .determine the acceleration of the bike.

sergeinik [125]

Given: Change of x is 35.4m, Velocity Final=7.10 m/s, Velocity Initial=0m/s
Find: Acceleration
Analysis:
Vf²=Vi²+2aΔx (Velocity final squared equals Velocity initial squared plus 2 times acceleration times change of x)
(7.10 m²/s)²=(0 m/s)²+2a(35.4 m)
50.41 m/s²=(70.8 m)a
a=0.712 m/s²

5 0

3 years ago

A rock is thrown off a 50.0 m high cliff. How fast must the rock leave the cliff top to land on level ground below, 90 m from th

blagie [28]

Answer:

The rock must leave the cliff at a velocity of 28.2 m/s

Explanation:

The position vector of the rock at a time t can be calculated using the following equation:

r = (x0 + v0x · t, y0 + 1/2 · g · t²)

Where:

r = position vector at time t.

x0 = initial horizontal position.

v0x = initial horizontal velocity.

t = time.

g = acceleration due to gravity (-9.81 m/s² considering the upward direction as positive).

Please, see the attached figure for a graphical description of the problem. Notice that the origin of the frame of reference is located at the edge of the cliff so that x0 and y0 = 0.

When the rock reaches the ground, the position vector will be (see r1 in the figure):

r1 = (90 m, -50 m)

Then, using the equation of the vector position written above:

90 m = x0 + v0x · t

-50 m = y0 + 1/2 · g · t²

Since x0 and y0 = 0:

90 m = v0x · t

-50 m = 1/2 · g · t²

Let´s use the equation of the y-component of the vector r1 to find the time it takes the rock to reach the ground and with that time we can calculate v0x:

-50 m = 1/2 · g · t²

-50 m = -1/2 · 9.81 m/s² · t²

-50 m / -1/2 · 9.81 m/s² = t²

t = 3.19 s

Now, using the equation of the x-component of r1:

90 m = v0x · t

90 m = v0x · 3.19 s

v0x = 90 m / 3.19 s

v0x = 28.2 m/s

8 0

3 years ago

Describe the two main ways that energy travels through the Sun.

ValentinkaMS [17]

Answer:

The energy are traveled through the sun in two ways that are:

By the radiation
By the convection

As, the energy are first traveled outward from the core of the sun and then it get entered in the zone of the radiation and this zone is known as radiative zone in the surface of the sun.In the radiation process some amount of the hydrogen particle are combined and then releases the energy. And the convection is the process of conversion of one form of energy to another form.

7 0

3 years ago

Give reasons.<br>a) Sunlight does not fall on the ground where cloud forms shadow.

Viefleur [7K]

Answer:

Sunlight passing through a cloud is scattered in various directions. Some photons eventually find their way out the bottom of the cloud, some are reflected upwards, and some are absorbed, serving to warm the cloud. Since only a fraction of the light makes it to ground level, you have a shadow.

Explanation:

Hope it helps you

4 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