I ship travels north at 15 km an hour for five hours what is the ships this placement in kilometers

algol13

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6 0

2 years ago

a person throws a ball upward into the air with an initial velocity of 20 m/s. calculate (a) how high it goes, and (b) how long

Phantasy [73]

Answer:

a) about 20.4 meters high

b) about 4.08 seconds

Explanation:

Part a)

To find the maximum height the ball reaches under the action of gravity (g = 9.8 m/s^2) use the equation that connects change in velocity over time with acceleration.

$a=\frac{Vf-Vi}{t}$

$-9.8 \frac{m}{s} =\frac{Vf-Vi}{t}$

In our case, the initial velocity of the ball as it leaves the hands of the person is Vi = 20 m/s, while thw final velocity of the ball as it reaches its maximum height is zero (0) m/s. Therefore we can solve for the time it takes the ball to reach the top:

$-9.8 =\frac{0-20}{t}\\t=\frac{20}{9.8} s = 2.04 s$

Now we use this time in the expression for the distance covered (final position Xf minus initial position Xi) under acceleration:

$Xf-Xi=Vi*t+\frac{1}{2} a t^{2} \\Xf-Xi=20*(2.04)-\frac{1}{2} 9.8*2.04^{2}\\Xf-Xi=20.408 m$

Part b) Now we use the expression for distance covered under acceleration to find the time it takes for the ball to leave the person's hand and come back to it (notice that Xf-Xi in this case will be zero - same final and initial position)

$Xf-Xi=0=20*(t)-\frac{1}{2} 9.8*t^{2$

To solve for "t" in this quadratic equation, we can factor it out as shown:

$0= t(20-\frac{9.8}{2} t)$

Therefore there are two possible solutions when each of the two factors equals zero:

1) t= 0 (which is not representative of our case) , and

2) the expression in parenthesis is zero:

$0= 20-\frac{9.8}{2} t\\t=\frac{20*2}{9.8} = 4.08 s$

7 0

3 years ago

Which of these is NOT a common building material?

Over [174]

B Quartz. Will be your answer of thia

8 0

3 years ago

Read 2 more answers

If you hold a bar magnet in each hand and bring your hands together, will the force be attractive or repulsive if the magnets ar

Law Incorporation [45]

a) The force is repulsive

b) The force is attractive

Explanation:

Every magnet has a magnetic field around it. It is possible to distinguish two different poles in the magnet, according to the direction of the magnetic field: in particular, the lines of the field go out from the North pole and go into the South Pole. When a magnet is broken, two new magnets are formed, each of them having its own north and south pole.

The force between two magnets can be either attractive or repulsive, depending on which poles are facing each other. We have the following situation:

The magnetic force between two like poles (north-north and south-south) is repulsive
The magnetic force between two opposite poles (north-south) is attractive

Therefore, we have the following situations in this problem:

a)

Here we are holding the two north poles together: since they are like poles, they repel each other, so the force in this case is repulsive

b)

Here we are holding a north pole and a south pole together: since they are opposite poles, they attract each other, so the force in this case is attractive

Learn more about magnetic fields:

brainly.com/question/3874443

brainly.com/question/4240735

#LearnwithBrainly

5 0

3 years ago

Momentum depends on what two factors

IrinaVladis [17]

mass and velocity

Explanation:

Momentum depends on two important factors which are the mass and velocity of a body.

Momentum = mass x velocity

Momentum can be defined as the product of mass and velocity.
It is a vector quantity that has both magnitude and directions.
Momentum is a very important quantity in physics as it shows the impact of a force on another.
The unit is Kgm/s²
It is the same as impulse.

learn more:

Momentum brainly.com/question/2990238

#learnwithBrainly

3 0

3 years ago