If the net force on an object is in a negative direction, what will the direction of the resulting acceleration be

You stand on a frictional platform that is rotating at 1.8 rev/s. Your arms are outstretched, and you hold a heavy weight in eac

dusya [7]

Answer:

20.62361 rad/s

489.81804 J

Explanation:

$I_i$ = Initial moment of inertia = 9.3 kgm²

$I_f$ = Final moment of inertia = 5.1 kgm²

$\omega_i$ = Initial angular speed = 1.8 rev/s

$\omega_f$ = Final angular speed

As the angular momentum of the system is conserved

$I_i\omega_i=I_f\omega_f\\\Rightarrow \omega_f=\dfrac{I_i\omega_i}{I_f}\\\Rightarrow \omega_f=\dfrac{9.3\times 1.8}{5.1}\\\Rightarrow \omega_f=3.28235\ rev/s=3.28235\times 2\pi=20.62361\ rad/s$

The resulting angular speed of the platform is 20.62361 rad/s

Change in kinetic energy is given by

$\Delta K=\dfrac{1}{2}(I_f\omega_f^2-I_i\omega_i^2)\\\Rightarrow \Delta K=\dfrac{1}{2}(5.1\times (20.62361)^2-9.3\times (1.8\times 2\pi)^2)\\\Rightarrow \Delta K=489.81804\ J$

The change in kinetic energy of the system is 489.81804 J

As the work was done to move the weight in there was an increase in kinetic energy

6 0

3 years ago

The angle a vector makes with the x-axis of a coordinate system must be what size in order to make one or more of its components

Aneli [31]

If only 1 option is correct then it is (D)
All the others can also make one component negative, all depends how u measured the angle.
all the best

3 0

3 years ago

Read 2 more answers

1.) Waves transfer ______ without moving ______

kondor19780726 [428]

I believe it goes as the following::

1) Waves transfer energy without moving particles

2) The two types of waves are longitudinal and transverse waves OR The two types of waves are mechanical and electromagnetic waves. Both are applicable and should be correct!

6 0

3 years ago

A wheelbarrow can be used to help lift a load, such as a pile of dirt, and then push the load across a distance. A man pushes a

skelet666 [1.2K]

Answer:

B.) a wheel and axle and a lever

Explanation:

P.S - The exact question is -

Given - A wheelbarrow can be used to help lift a load, such as a pile of dirt, and then push the load across a distance. A man pushes a wheelbarrow.

To find - Which simple machines make up a wheelbarrow?

A.) a pulley and an inclined plane

B.) a wheel and axle and a lever

C.) a pulley and a wheel and axle

D.) a lever and a wedge

Proof -

The correct option is - B.) a wheel and axle and a lever

Wheelbarrows are used to carry more goods from place to place by using minimal force as compared when goods are carried by hand.

With this machine, During hauling people can save time.

4 0

2 years ago

Read 2 more answers

A car traveling in a straight line has a velocity of 5.0 m/s. After an acceleration of 0.75 m/s/s, the cars velocity is 8.0. In

Bogdan [553]

Vs - velocity on beginning
ve - velocity on ending. You've got:
$v_s = 5 \frac{m}{s} \\ v_e=8 \frac{m}{s} \\ \hbox{Then:} \\ \Delta v=v_e - v_s = 8 \frac{m}{s} - 5\frac{m}{s}=3 \frac{m}{s} \\ a=0,75 \frac{m}{s^2} \\ \hbox{And from formula:} \\ a=\frac{\Delta v}{\Delta t} \qquad \Rightarrow \qquad \Delta t= \frac{\Delta v}{a} \\ \hbox{Substitute:} \\ \Delta t=\frac{3\frac{m}{s}}{0,75 \frac{m}{s^2}}= \frac{3}{\frac{3}{4}} s= 3 \cdot \frac{4}{3} s= 4 s$
So he needed 4 second.

3 0

3 years ago