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2 years ago

Helllppp mee!

Physics

2 answers:

Fed [463]2 years ago

5 0

Given:

m = 0.14 kg

v = 18 m/s

To find:

Kinetic energy= ?

Explanation:

Kinetic energy of the object is possessed when the object is in motion. It is define as the work done required to accelerate a body from rest to motion. Unit of energy is Joule and it is same as unit of work done. Energy is nothing but the capacity to do work.

Solution:

Kinetic energy of the ball is given by,

Kinetic energy = $\frac{1}{2}m v^{2}$

m = 0.14 kg

v = 18 m/s

Kinetic energy = $\frac{1}{2}(0.14) (18)^{2}$

Kinetic energy = 226.8 Joule

aleksandr82 [10.1K]2 years ago

4 0

KE = 0.5mv²
KE = 0.5 * 0.14kg * 18² m/s
KE = 22.68 J

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A box slides down a frictionless ramp.if it starts at rest, what is it’s speed at the bottom?

zhenek [66]

8.854 m/s is the speed of the box after it reaches bottom of the ramp.

<u>Explanation</u>:

From the figure we came to know that height of the block is 4 m.

We know that,

Total "initial energy of an object" = Total "final energy of an object "

Total "initial energy of an object" is = "sum of potential energy" and "kinetic energy" of an object at its initial position.

$\text { "g" acceleration due to gravity is } 9.8 \mathrm{m} / \mathrm{s}^{2}$

$\text { Total initial energy }=\mathrm{m} \times \mathrm{g} \times \mathrm{h}_{\mathrm{i}}+\frac{1}{2} \mathrm{m} v_{i}^{2}$

Initial velocity is “0” as the object does not have starting speed

$\text { Height of the block where the object is placed initially }\left(h_{i}\right) \text { is } 4 \mathrm{m} \text { . }$

$\text { Total initial energy }=\mathrm{m} \times 9.8 \times 4+\frac{1}{2} \mathrm{m} 0^{2}$

Total initial energy = 39.2 × m

$\text { Total final energy }=\mathrm{m} \times \mathrm{g} \times \mathrm{h}_{\mathrm{f}}+\frac{1}{2} m v_{f}^{2}$

$\text { We need to find final velocity } v_f$

$\text { Height of the block where the object is travelled to bottom (h_) is } 0 \mathrm{m} \text { . }$

$\text { Total final energy }=\mathrm{m} \times 9.8 \times 0+\frac{1}{2} m v_{f}^{2}$

Now, Total initial energy of an object = Total final energy of an object

$39.2 \times \mathrm{m}=0.5 \mathrm{m} v_{f}^{2}$

$\frac{39.2}{0.5}=v_{f}^{2}$

$v_{f}^{2}=78.4$

$v_{f}=\sqrt{78.4}$

$v_{f}=8.854 \mathrm{m} / \mathrm{s}$

Final speed is 8.854 m/s.

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2 years ago

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inysia [295]

Answer: 120 volts

Explanation:

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2 years ago

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PilotLPTM [1.2K]

The minimum velocity of the Salmon jumping at the given angle is 12.3 m/s.

The given parameters;

height of the waterfall, h = 0.432 m
distance of the Salmon from the waterfall, s = 3.17 m
angle of projection of the Salmon, = 30.8º

The time of motion to fall from 0.432 m is calculated as;

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