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2 years ago

11

A man throws a ball vertically upward with an initial speed of 20m/s. What is the maximum height reached by the ball and how lon

g does it take to return to the point it was thrown?

1 answer:

Luba_88 [7]2 years ago

8 0

Answer:

It's your first question!!!

Explanation:

Enjoy it!!!

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The 2.6-kg collar is released from rest at A and slides down the inclined fixed rod in the vertical plane. The coefficient of ki

neonofarm [45]

Answer:

The attached diagram explains the system,

Sum of Fy = 0

N=9.81

N - mgCos60 = 0

F= ukN= (0.53)(9.81) =

F= 5.12 N

So

F.d= 1/2(mv.v) - mgdsin60

-5.12*0.5 = 0.5*v^2 - 2*(9.81)*(0.5*sin60)

(a) v = 2.436 m/s

For deflection

-F.x = 1/2(mv.v) - mgxsin60 + 1/2 (k*x*x)

by solving for with values of v, m, g, F, k

800x^2 - 11.87 x - 5.938 = 0

by solving the quadratic equation

x = 0.093, -0.079

(b) x = 0.093 m

correct Answer is 0.093m

Explanation:

3 0

3 years ago

Since entropy is about how energy is shared, it is important to be able to identify places where energy can be put, or degrees o

Fiesta28 [93]

Answer:

Please see answer in explanation

Explanation:

1. Since each molecule has three kinetic degrees of freedom (can move in three independent directions), the gas must have 3N DoFs.

2. Each molecule has the three kinetic degrees of freedom the monotonic atom has moving without rotating but it can also spin. There are three axes for it to spin around so we would expect three rotational degrees of freedom, but as were as above, the one about the diatomic molecule's axis doesn't count because of quantum. So we have two rotational DoFs and three kinetic, for a total of 5 per molecules. So the gas will have 5N DoFs.

3.When a spring vibrates it has two DoFs, its KE and its PE, so adding 1 vibration adds 2 DoFs per molecule, giving 7 per molecule and giving thegas 7N DoFs.

6 0

3 years ago

Which of the following is the best reason for using a scanning electron microscope?

torisob [31]

Answer is C: Ability to see three-dimensional images of the surfaces of object

Explanation:

To enable the technician see fractures and broken particles in a better resolution as the SEM sees the peaks and valley of the structure.

8 0

3 years ago

Initially (at time t = 0) a particle is moving vertically at 7.5 m/s and horizontally at 0 m/s. Its horizontal acceleration is 1

Lelu [443]

Answer:

t = 0.657 s

Explanation:

given,

initial vertical velocity = 7.5 m/s

initial horizontal velocity = 0 m/s

angle = 49◦

using kinetic equation

final velocity in vertical direction

v sinθ = u_y - gt ........................(1)

final velocity in horizontal direction

v cosθ = u_x + a_x × t

here u_x = 0.0 m/s

v cosθ = a_x×t ......................(2)

Dividing equation (1) / (2)

$tan \theta =\dfrac{u_y - gt}{a_x\times t}$

solving for time t

$t = \dfrac{u_y}{tan \theta \times a_x + g}$

u_y = initial velocity along x direction

acceleration along a_x = 1.4 m/s²

g = acceleration due to gravity = 9.8 m/s²

θ = 43° , u_y = 7.5 m/s

$t = \dfrac{7.5}{tan 49^0\times 1.4+ 9.8}$

t = 0.657 s

time taken by the particle is t = 0.657 s

6 0

3 years ago

C biến thiên để Uc cực đại

lesya692 [45]

Muy bien si muy bien

4 0

3 years ago