Pls help me fast and correct

During soccer practice, Maya kicked a soccer ball 37° off the ground at 25 m/s. Max, the goalie, caught the ball 60 m away from

amid [387]

Answer:

3.0 seconds

Explanation:

We can solve the problem by considering the horizontal motion of the ball only. In fact, the ball moves by uniform motion (constant speed) along the horizontal direction, since there are no forces acting in this direction. The horizontal speed of the ball is given by:

$v_x = v_0 cos \theta = (25 m/s)(cos 37^{\circ})=19.97 m/s$

and it does not change during the motion.

We also know that the ball travels a horizontal distance of d = 60 m, so we can find the time it takes to cover the distance by using the equation:

$t=\frac{d}{v}=\frac{60 m}{19.97 s}=3.0 s$

8 0

3 years ago

Read 2 more answers

Your friend says, “chemical changes are caused by an input in energy. In physical changes, there is no transfer of energy” is yo

nalin [4]

Answer:

Ok, let's suppose the simplest of the physical changes:

We have an object that is not moving (so it is not accelerated)

and there is change, now the object moves.

Because there was a change, means that there was an acceleration, and by the second Newton's law.

Force equals mass times acceleration:

F = m*a

There must be a force.

So suppose that you pushed the object, then some energy that you had, you transferred it to the object, that now is moving and now has kinetic energy.

Now, is kinda true that in a closed system the total energy is always constant, but it depends on what is our system.

So if we think in our system as you and the object, then in the whole system the energy does not change because the energy that you lost is now on the object, but again, there was a transfer of energy.

So no, your friend is not correct.

3 0

3 years ago

Responsibilities of a class are derived from ________________.

mihalych1998 [28]

Answer:

The correct option is a behavioural models of the the to-be system.

Explanation:

As the Use case analysis method generates the analysis classes list such that the classes are capable of performing the behavior needed to make the system function successfully. From these analysis classes list the responsibilities of each class are defined.

As the list is derived from the behavioural models of the system, thus option a is the correct option.

7 0

3 years ago

HELP ME!!! NO LINKS!!! Compare and Contrast the scientific definitions of theory and law. Explain why the first law of thermodyn

Nataly_w [17]

The date the model was published.

The use of “laws” originated prior to science splitting from natural philosophy. There’s an implicit assumption that God as the creator laid down both moral and natural laws, with the theologian concerned with the former and the natural philosopher concerned with the latter.

“Theory” begins to take hold in the late 1700s and, very roughly speaking, is used to describe more complex models. “Law” eventually became nearly archaic, although still used to describe very pithy models (Amdahl’s Law, Gustafson’s Law).

The word “model” is gradually superseding both of them.

People have tried to come up with hard-and-fast rules to distinguish them, but scientists are unruly beasts, and use whatever language suits them in the moment.

3 0

2 years ago

A cylindrical cistern, constructed below ground level, is 2.9 m in diameter and 2.0 m deep and is filled to the brim with a liqu

Tomtit [17]

Answer:

15.1 m

Explanation:

We first calculate the apparent depth from

refractive index, n = real depth/apparent depth

apparent depth, a = real depth/refractive index

real depth = 2.0 m, refractive index = 1.4

apparent depth, a = 2.0/1.4 = 1.43 m

Since the cylindrical cistern has a diameter of 2.9 m, its radius is 2.9/2 = 1.45 m

The angle of refraction, r is thus gotten from the ratio

tan r = radius/apparent depth = 1.45/1.43 = 1.014

r = tan⁻¹(1.014) = 45.4°

The angle of incidence, i is gotten from n = sin i/sin r

sin i = nsin r = 1.4sin45.4° = 1.4 × 0.7120 = 0.9968

i = sin⁻¹(0.9968) = 85.44°

Since the girl's eyes are 1.2 m from the ground, the distance ,h from the edge of the cistern she must stand is gotten from

tan i = h/1.2

h = 1.2tan i = 1.2tan85.44° = 1.2 × 12.54 = 15.05 m

h = 15.05 m ≅ 15.1 m

So, she must stand 15.1 m away from the edge of the cistern to still see the object.

4 0

3 years ago

Pls help me fast and correct ​

Pls help me fast and correct