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3 years ago

What is the final velocity of a 10 kg object that drops from rest and falls for 30 seconds?

1 answer:

8 0

The object is in free fall, so its velocity follows the law:
$v(t) = v_0 + gt$
where
$v_0$ is the initial velocity (zero)
g is the gravitational acceleration
t is the time

Since the initial velocity is zero, the velocity after t=30 s is
$v(30 s)=gt=(9.81 m/s^2)(30 s)=294.3 m/s$

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A solid cylinder is released from the top of an inclined plane of height 0.81 m. From what height, in meters, on the incline sho

Jlenok [28]

Answer:

same 0.81m

Explanation:

in this problem if we assume there no resistance of any sort. and we apply the energy conservation

change in Potential energy = change in kinetic energy

mgh = 0.5mv^2

gh = 0.5v^2

the above relation suggests that the speed at the bottom is only depending on the height it is released from not on the shape, mass or radius.

so at the bottom

put h = 0.81m

9.81 * 0.81 * 2 = v^2

v=3.99 m/s

both CYLINDER and SPHERE will have same velocity at the bottom if released from the same height irrespective of shape and size

3 0

3 years ago

HEY CAN ANYONE PLS ANSWER DIS!!!!!!!!!!!!

Salsk061 [2.6K]

Answer:

a is falsa

Explanation:

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2 years ago

A truck accidentally rolls down a driveway for 8.0\,\text m8.0m8, point, 0, start text, m, end text while a person pushes agains

gavmur [86]

Answer:

Explanation:

According to work energy theorem

change in kinetic energy of truck = work done against it

work done against it = force x displacement

= - 850 x 8 = 6800 J

change in kinetic energy of truck = - 6800 J .

energy will be reduced by 6800 J

5 0

3 years ago

How would a spinning disk's kinetic energy change if its moment of inertia was five times larger but its angular speed was five

Keith_Richards [23]

Answer:

The kinetic energy of a spinning disk will be reduced to a tenth of its initial kinetic energy if its moment of inertia is made five times larger, but its angular speed is made five times smaller.

Explanation:

Let us first consider the initial characteristics of the angular motion of the disk

moment of inertia = $I$

angular speed = ω

For the second case, we consider the characteristics to now be

moment of inertia = $5I$ (five times larger)

angular speed = ω/5 (five times smaller)

Recall that the kinetic energy of a spinning body is given as

$KE = \frac{1}{2}Iw^{2}$

therefore,

for the first case, the K.E. is given as

$KE = \frac{1}{2}Iw^{2}$

and for the second case, the K.E. is given as

$KE = \frac{1}{2}(5I)(\frac{w}{5} )^{2} = \frac{5}{50}Iw^{2}$

$KE = \frac{1}{10}Iw^{2}$

this is one-tenth the kinetic energy before its spinning characteristics were changed.

This implies that the kinetic energy of the spinning disk will be reduced to a tenth of its initial kinetic energy if its moment of inertia is made five times larger, but its angular speed is made five times smaller.

6 0

3 years ago

Name the physical quantity which changes contenously during uniform-circular motion.

kumpel [21]

The direction of the motion is constantly changing during
motion over any closed path, not only circular.

8 0

3 years ago