All categories

3 years ago

A brick is dropped from a high scaffold. a. What is its velocity after 4.0s ?

Physics

1 answer:

Ilia_Sergeevich [38]3 years ago

6 0

Answer:

A: 1.962

B: 3.924

Explanation:

g = G *M /R^2

g = 9.807*M/R^2 the gravitational constant of ground level on earth is about 9.807

g = 9.807*5lbs/R^2 the average brick is about 5 pounds.

g = 9.807*5*10^2. I'm assuming the height is around ten feet to help you out.

with these numbers plugged in you get an acceleration of 0.4905 a final velocity after 4 seconds 1.962. It's height fallen after 4 seconds is 3.924.

( M = whatever the brick weighs it's not specified in the question)

(R = the distance from the ground or how high the scaffold is)

(hopefully you can just plug your numbers in there hope this helps)

You might be interested in

Velocity can best be described by which of the following statements?

pogonyaev

Answer: Velocity can best be described as, the speed in a given direction.

Explanation: To find the answer, we need to know more about the Velocity of a body.

<h3>What is Velocity of a body?</h3>

Velocity is the rate of change of displacement.
It's a vector quantity and is measured in m/s.
It can be positive, negative or zero.
A body is said to be in uniform motion, then its velocity remains constant.
Change in velocity can be a change in speed.
The magnitude of velocity is less than or equal to speed.

Thus, we can conclude that, the option C is best describing velocity.

Learn more about velocity here:

brainly.com/question/28108466

#SPJ4

8 0

2 years ago

Read 2 more answers

An object at rest cannot remain at rest unless which of the following holds?View Available Hint(s)An object at rest cannot remai

Leni [432]

Answer:

True The net force must be zero for the acceleration to be zero

Explanation:

In order to analyze the statements of this problem we propose your solution.

First let's look at Newton's first, which stable that every object is at rest or with constant speed unless something takes it out of this state (acceleration)

Now let's look at the second postulate, which says that force is related to the product of the mass of a body and its acceleration.

As a result of these two laws, for a body is a constant velocity the summation force on it must be zero.

Now we can analyze the statements given.

True The net force must be zero for the acceleration to be zero

False. If the force is different from zero, there is acceleration that changes the speeds

False. There may be forces, but the sum of them must be zero

False. If a force acts, the acceleration is different from zero and the speed changes

5 0

3 years ago

If five joules were required to move a crate in 3.7 seconds, what power was applied?

AleksAgata [21]

Answer:

The answer to your question is 1.35 Watts

Explanation:

Data

Work = W = 5 J

time = t = 3.7 s

Power = P = ?

Formula

Power is a rate in which work is done or energy is transferred over time

P = $\frac{W}{t}$

Substitution

$P = \frac{5}{3.7}$

Result

P = 1.35 W

8 0

3 years ago

A very hard rubber ball (m = 0.5 kg) is falling vertically at 4 m/s just before it bounces on the floor. The ball rebounds back

saw5 [17]

Answer:

The force exerted by the floor is 80 N.

Explanation:

Given that,

Mass of ball = 0.5 kg

Velocity= 4 m/s

Time t = 0.05 s

When the ball rebounds then the kinetic energy is

$K.E =\dfrac{1}{2}mv^2$

Where, m = mass of ball

v = velocity of ball

Put the value into the formula

$K.E=\dfrac{1}{2}\times0.5\times(4)^2$

$K.E = 4\ J$

The average force exerted by the floor on the ball = change in kinetic energy over collision time

$F = \dfrac{4}{0.05}$

$F=80\ N$

Hence, The force exerted by the floor is 80 N.

4 0

3 years ago

A bicycle traveled 150 meters west from point A to point B. Then It took the same route and came back to point A. It took a tota

Julli [10]

Answer:

Option D. The average speed is 2.5 meters/second, and the average velocity is 0 meters/second.

Explanation:

we know that

To find out the average speed divide the total distance by the total time

Let

d -----> the total distance in meters

t -----> the time in seconds

s ----> the speed in meters per second

$s=\frac{d}{t}$

Remember that

$1\ min=60\ sec$

we have

$t=2\ min=2(60)=120\ sec$

$d=150(2)=300\ m$

substitute

$s=\frac{300}{120}$

$s=2.5\frac{m}{sec}$

<u><em>Find out the average velocity</em></u>

To find out the average velocity divide the displacement) by the time

The displacement is the distance from the start point to the end point regardless of the route

In this problem

The start point is A and the end point is A

The displacement is equal to zero

therefore

The average velocity is 0 m/sec

6 0

3 years ago