All categories

3 years ago

Please Help! A ball is thrown straight up from the ground. What way does its acceleration point at the top?

Physics

1 answer:

QveST [7]3 years ago

3 0

Answer: A. Vertical

Explanation:

If the ball is thrown straight up from the ground (asuming the ground as height 0), this means its initial velocity is greater than zero.

While the ball rises and gains height, its velocity decreases until it reaches its maximum height where it stops (velocity equal to zero) and then it begins to fall to the ground.

Now, during all the movement, the ball has an acceleration, which is the acceleration due gravity (9.8 m/s^{2} on Earth), even at the top or maximum height (when the ball stops just for fraction of time), and this acceleration points vertical and downward to the Earth's center.

You might be interested in

An object at rest on a flat, horizontal surface explodes into two fragments, one seven times as massive as the other. The heavie

Arte-miy333 [17]

Answer:

the distance d traveled by the lighter fragment is 58.1 m.

Explanation:

mass of the lighter fragment = m

the lighter fragment traveled a distance = ?

mass of the heavier fragment = 7m

the distance covered by the heavier fragment = 8.30 m

The two particles will be given the same amount of energy from the explosion. This energy is used to do work by the two fragments.

work done by heavier fragment w = mgd

where m is the mass

g is acceleration due to gravity

d is the distance traveled.

substituting, the work done by the heavier fragment is

w = 7m x g x 8.3 = 58.1mg

The same way, the lighter fragment does work of

w = mgd

equating the two work done since they are given the same amount of energy from the explosion, we have

58.1mg = mgd

mg cancels out, we have

the distance d traveled by the lighter fragment d = 58.1 m

8 0

3 years ago

A 80kg astronaut is training in human centrifuge to prepare for a launch. The astronaut uses the centrifuge to practice having a

inessss [21]

The answers on the model of the human centrifuge ready for the launch to each question of the statement are listed below:

a) A force of 2479.210 newtons is acting on the astronaut's back.

b) A net centripetal force of 2479.210 newtons is acting on the astronaut.

c) The centripetal acceleration of the astronaut is 30.990 meters per square second.

d) The astronaut has a linear speed of approximately 19.284 meters per second.

e) The angular speed of the astronaut is 1.607 radians per second (15.346 revolutions per minute).

<h3>How to apply Newton's laws to analyze a process in a human centrifuge training</h3>

The human centrifuge experiments a centripetal acceleration when it reaches a peak angular speed. In this question we must apply Newton's laws of motion and concepts of centripete and centrifugal forces to answer the questions. Now we proceed to answer the questions:

<h3>How much force is acting on the astronaut's back?</h3>

By the third Newton's law the astronaut experiments a rection force (F), in newtons, which has the same magnitude to centrifugal force but opposed to that force. The magnitude of the force acting on the back of the astronaut is equal to:

$F = 3.16\cdot (80\,kg)\cdot \left(9.807\,\frac{m}{s^{2}} \right)$

$F = 2479.210\,N$

A force of 2479.210 newtons is acting on the astronaut's back. $\blacksquare$

<h3>What is the net centripetal force on the astronaut?</h3>

By the second and third Newton's laws we know that the net centripetal force on the astronaut is equal to the magnitude of the force found in the previous question. Thus, a net centripetal force of 2479.210 newtons is acting on the astronaut. $\blacksquare$

<h3>What is the astronaut's centripetal acceleration?</h3>

The centripetal acceleration of the astronaut (a), in meters per square second, is found by dividing the result of the previous question by the mass of the astronaut (m), in kilograms:

$a = \frac{F}{m}$ (1)

If we know that F = 2479.210 newtons and m = 80 kilograms, then the centripetal acceleration of the astronaut is:

$a = \frac{2479.210\,N}{80\,kg}$

$a = 30.990\,\frac{m}{s^{2}}$

The centripetal acceleration of the astronaut is 30.990 meters per square second. $\blacksquare$

<h3>What is the astronaut's linear speed?</h3>

By definition of uniform circular motion, we have the following formula for the linear velocity of the astronaut (v):

$v = \sqrt{a\cdot r}$ (1)

Where r is the radius of the human centrifuge, in meters.

If we know that $a = 30.990\,\frac{m}{s^{2}}$ and $r = 12\,m$ , then linear velocity of the astronaut is:

$v = \sqrt{\left(30.990\,\frac{m}{s^{2}} \right)\cdot (12\,m)}$

v ≈ 19.284 m/s

The astronaut has a linear speed of approximately 19.284 meters per second. $\blacksquare$

<h3>What is the astronaut's angular speed? </h3>

The angular speed of the astronaut (ω), in radians per second, is found by the following kinematic relationship:

$\omega = \frac{v}{R}$ (1)

If we know that v ≈ 19.284 m/s and R = 12 m, then the angular speed is:

$\omega = \frac{19.284\,\frac{m}{s} }{12\,m}$

ω = 1.607 rad/s (15.346 rev/m)

The angular speed of the astronaut is 1.607 radians per second (15.346 revolutions per minute). $\blacksquare$

To learn more on centripetal forces, we kindly invite to check this verified question: brainly.com/question/11324711

6 0

2 years ago

If it takes 600 N to move a box 5 meters, how much work is done on the box?

Arada [10]

Answer:3000joules

Explanation: work=force×distance

Work=600×5

Work=3000joules

6 0

4 years ago

Which activity directly converts energy from the Sun into chemical energy?

umka21 [38]

The biological process that directly converts energy from the Sun into chemical energy would be Photosynthesis. It is a process carried out by autotrophic organisms which are predominantly plants and other photosynthetic bacteria.

4 0

3 years ago

Find the net force on Each box

777dan777 [17]

1. 40 n

2. 25 n

Im sorry if it is wrong

5 0

3 years ago

Read 2 more answers