A 4kg rock isn’t rolling 10m/s. Find it’s kinetic energy.

1 answer:

3 0

Kinetic energy = (1/2) (mass) (speed)²

The rock's kinetic energy is not

(1/2) (4 kg) (10 m/s)²

= (1/2) (4 kg) (100 m²/s²)

= 200 Joules .

It may be more, or it may be less. The only thing
we can be sure of is that it is not 200 Joules.

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A 0.358 kg particle slides around a horizontal track. The track has a smooth, vertical outer wall forming a circle with a radius

oee [108]

Answer:

The energy loss due to friction in one revolution is 4.92 J.

Explanation:

Given that,

Mass of particle = 0.358 kg

Radius = 1.66 m

Initial speed =8.19 m/s

Final speed = 6.29 m/s

We need to calculate the kinetic energy

Using formula of kinetic energy

$\Delta K.E=\dfrac{1}{2}m(v_{f}^2-v_{i}^2)$

Put the value into the formula

$\Delta K.E=\dfrac{1}{2}\times0.358\times(8.19^2-6.29^2)$

$\Delta K.E=4.92\ J$

Hence, The energy loss due to friction in one revolution is 4.92 J.

4 0

3 years ago

A car is moving with a uniform velocity.find out the force of which it is moving

olya-2409 [2.1K]

If a car is moving with uniform velocity, then there is
no net force acting on it.

The force of the engine is exactly enough to balance
the forces of friction and air resistance against the car.

Also notice that there can't be any centripetal force, and the
car can't be on a curve. If it's moving with "uniform velocity",
that means steady speed in a straight line.

7 0

3 years ago

A 5 kg bucket is lifted from the ground into the air by pulling in 10 meters of rope with linear density of 2 kg/m at a constant

iren [92.7K]

Answer:

Workdone W = 1465.1 J

Explanation:

The weight of the water = density × volume

weight of the water = 1000 kg/m³ × 100 cm³

weight of the water = 1000 kg/m³ × 0.0001 m³

weight of the water = 0.1 kg

weight of the bucket = 5 kg