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3 years ago

PLZ HELP ME i don’t get this

Physics

1 answer:

Scorpion4ik [409]3 years ago

4 0

Explanation:

(i) Height of tree, h = 4 m

Mass of Ninja, m = 30 kg

The gravitational potential energy on the top branch of the tree is given by :

$P=mgh$

g is acceleration due to gravity

$P=30\ kg\times 9.8\ m/s^2\times 4\ m\\\\P=1176\ J$

(ii) If he were at a height of 2 meters from the ground, its potential energy will be :

$P=mgh$

g is acceleration due to gravity

$P=30\ kg\times 9.8\ m/s^2\times 2\ m\\\\P=588\ J$

Therefore, this is the required explanation.

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3 years ago

A charge alters the space around it. What is this alteration of space called? Electric ether Electric Force Electric field Charg

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Explanation:

A charge alters the space around it. This alteration of space is called the electric field. It is also defined as the electric force acting on a charged particle per unit test charge. It is given by :

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3 years ago

The lawn sprinkler consists of four arms that rotate in the horizontal plane. The diameter of each nozzle is 8 mm, and the water

sashaice [31]

Answer: the constant angular velocity of the arms is 86.1883 rad/sec

Explanation:

First we calculate the linear velocity of the single sprinkler;

Area of the nozzle = π/4 × d²

given that d = 8mm = 8 × 10⁻³

Area of the nozzle = π/4 × (8 × 10⁻³)²

A = 5.024 × 10⁻⁵ m²

Now total discharge is dived into 4 jets so discharge for single jet will be;

Q_single = Q / n = 0.006 / 4 = 1.5 × 10⁻³ m³/sec

So using continuity equation ;

Q_single = A × V_single

V_single = Q_single/A

we substitute

V_single = (1.5 × 10⁻³) / (5.024 × 10⁻⁵)

V_single = 29.8566 m/s

Now resolving the forces as shown in the second image,

Vt = Vcos30°

Vt = 29.8566 × cos30°

Vt = 25.8565 m/s

Finally we calculate the angular velocity;

Vt = rω

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from the given diagram, radius is 300mm = 0.3m

so we substitute

ω_single = 25.8565 / 0.3

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Therefore the constant angular velocity of the arms is 86.1883 rad/sec

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3 years ago