How does a balanced chemical equation show that mass is conserved?

A physics student stands on a cliff overlooking a lake and decides to throw a softball to her friends in the water below. She th

aliina [53]

Answer:

58.5 m

Explanation:

First of all, we need to find the total time the ball takes to reach the water. This can be done by looking at the vertical motion only.

The initial vertical velocity of the ball is

$u_y = u sin \theta$

where

u = 21.5 m/s is the initial speed

$\theta=33.5^{\circ}$ is the angle

Substituting,

$u_y = (21.5) sin 33.5^{\circ} =11.9 m/s$

The vertical position of the ball at time t is given by

$y = h + u_y t + \frac{1}{2}gt^2$

where

h = 13.5 m is the initial heigth

$g = -9.8 m/s^2$ is the acceleration of gravity (negative sign because it points downward)

The ball reaches the water when y = 0, so

$0 = h + u_yt +\frac{1}{2}gt^2\\0 = 13.5 +11.9 t - 4.9t^2$

Which gives two solutions: t = 3.27 s and t = -0.84 s. We discard the negative solution since it is meaningless.

The horizontal velocity of the ball is

$u_y = u cos \theta = (21.5) cos 33.5^{\circ} =17.9 m/s$

And since the motion along the horizontal direction is a uniform motion, we can find the horizontal distance travelled by the ball as follows:

$d= u_x t = (17.9)(3.27)=58.5 m$

3 0

3 years ago

A 1000-kg whale swims horizontally to the right at a speed of 6.0 m/s. It suddenly collides directly with a stationary seal of m

anzhelika [568]

Answer:

Momentum after collision will be 6000 kgm/sec

Explanation:

We have given mass of the whale = 1000

Initial velocity v = 6 m/sec

It collides with other mass of 200 kg which is at stationary

Initial momentum of the whale = 1000×6 = 6000 kgm/sec

We have to find the momentum after collision

From conservation of momentum

Initial momentum = final momentum

So final momentum = 6000 kgm/sec

5 0

4 years ago

• Describe the main ideas of physical science

arlik [135]

Branch of science that studies matter and its motion through space and time, along with related concepts such as energy and force. Describing the nature, measuring and quantifying of bodies and their motion, and dynamics.

5 0

4 years ago

a woman walks south at a speed of 2.0mph for 60 minutes. She then turns around and walks north at a distance of 3000m in 25 minu

TiliK225 [7]

When a woman walks south at a speed of 2.0mph for 60 minutes. She then turns around and walks north at a distance of 3000m in 25 minutes. then the woman's average speed during her entire motion would be 73.15 meters /minute.

<h3>What is speed?</h3>

The total distance covered by any object per unit of time is known as speed.

the mathematical expression for speed is given by

speed = total; distance /total time

As given in the problem a woman walks south at a speed of 2.0mph for 60 minutes

60 min = 1 hour

1 mile = 1.60934 km

The distance covered by her southwards = speed ×time

=2 mph × 60 minutes

= 3.218 km

She then turns around and walks north at a distance of 3000m in 25 minutes

The distance covered northward is 3000m

speed = total distance /total time

=(3218 +3000) /(60+25)

=73.15 meters /minutes

Thus, The average speed of the woman would be 73.15 meters /minute.

Learn more about speed from here

brainly.com/question/13263542

#SPJ1

8 0

2 years ago

If an element is a semi-conductor, which classification correctly describes it?

stiks02 [169]

Metal

Explanation:

semiconductors are materials which have a conductivity between conductors (generally metals)

8 0

3 years ago