To a stationary observer, a bus moves south with a speed of 12 m/s. A man

Please help! A net force of 2.0 N acts on a 2.0-kg object for 10 seconds. What is the object’s kinetic energy after that 10 seco

padilas [110]

For Newton's second law, the force F applied to the object of mass m will cause an acceleration a of the body:
$F=ma$
So, the acceleration is
$a= \frac{F}{m}= \frac{2.0 N}{2.0 kg}=1 m/s^2$

The object undergoes through this acceleration for 10 seconds, t=10 s. Since it is an accelerated motion, we can find its final velocity after 10 seconds:
$v_f = v_i + at=0 m/s+(1m/s^2)(10 s)=10 m/s$
where $v_i$ is the initial velocity of the object, which is zero since it starts from rest.

Finally we can calculate the final kinetic energy of the object, which is given by
$K= \frac{1}{2}mv^2= \frac{1}{2}(2.0 kg)(10 m/s)^2=100 J$

7 0

3 years ago

A 5.0 g coin is placed 15 cm from the center of a turntable. The coin has static and kinetic coefficients of friction with the t

Alexandra [31]

Answer:

the coin does not slide off

Explanation:

mass (m) = 5 g = 0.005 kg

distance (r) = 15 cm = 0.15 m

static coefficient of friction (μs) = 0.8

kinetic coefficient of friction (μk) = 0.5

speed (f) = 60 rpm

acceleration due to gravity (g) = 9.8 m/s^{2}

lets first find the angular speed of the table

ω = 2πf

ω = 2 x π x 60 x $\frac{1}{60}$

ω = 6.3 s^{-1]

Now lets find the maximum static force between the coin and the table so we can get the maximum velocity the coin can handle without sliding

static force (Fs) = ma

static force (Fs) = μs x Fn = μs x m x g

Fs = 0.8 x 0.005 x 9.8 = 0.0392 N

Fs = ma

0.0392 = 0.005 x a

a = 7.84 m/s^{2}

$(Vmax)^{2}$ = a x r

$(Vmax)^{2}$ = 7.84 x 0.15

Vmax = 1.08 m/s

ωmax = $\frac{Vmax}{r}$

ωmax = $\frac{1.08}{0.15}$ = 7.2 s^{-1}

now that we have the maximum angular acceleration of the table, we can calculate its maximum speed in rpm

Fmax = $\frac{ωmax}{2π}$

Fmax = $\frac{7.2}{2 x π}$ = 68.7 rpm

since the table is rotating at a speed less than the maximum speed that the static friction can hold coin on the table with, the coin would not slide off.

4 0

4 years ago

The body needs small amounts of ________ to help enzymes break down proteins.

Inessa [10]

Answer:

I would say vitamin B-6

Explanation:

it is also known as pyridoxine. it helps ebzymes break down protein and carry the dismantled amino acids to the blood stream

Hope this helps ✌✌

4 0

3 years ago

Read 2 more answers

I need to calculate a coefficient of linear expansion given the following

Law Incorporation [45]

The coefficient of linear expansion is

(change of length, feet) / (original length, feet) per °F.

Since the numerator and denominator of the fraction have the same
unit, the coefficient turns out to be just a number, with no unit.

4 0

3 years ago

Civil engineers calculate suggested speeds around corners (those yellow signs) when designing roads based upon the ability of a

Rainbow [258]

The car shall not be successful since the corner must have a radius as nine times as the real corner designed for a suggested speed of 15 miles per hour.

By definition of centripetal acceleration, the square of the velocity taken by the vehicle ( $v$ ), in miles per hour, is directly proportional to the radius of the corner ( $R$ ), in meters. Then, we have the following relationship:

$\frac{v_{A}^{2}}{R_{A}} = \frac{v_{B}^{2}}{R_{B}}$ (1)

Where:

$v_{A}$ - Suggested velocity.
$v_{B}$ - Real velocity.
$R_{A}$ - Real radius of the corner.
$R_{B}$ - Expected radius of the corner.

If we know that $v_{A} = 15\,\frac{mi}{h}$ , $v_{B} = 45\,\frac{mi}{h}$ and $R_{A} = k$ , then the expected radius of the corner is:

$R_{B} = k\cdot \left(\frac{v_{B}}{v_{A}} \right)^{2}$

$R_{B} = 9\cdot k$

In order to successfully take a corner at 45 miles per hour, the corner must have a radius as nine times as the real corner designed for a suggested speed of 15 miles per hour. Thus, the car shall not be successful at a speed of 45 miles per hour.

To learn more on centripetal acceleration, we kindly invite to check this verified question: brainly.com/question/17689540

8 0

2 years ago