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2 years ago

Formula: KE = 1/2 my?

Physics

1 answer:

9966 [12]2 years ago

3 0

Answer:

22400 Joules

Explanation:

Apply the formula:

KE = 1/2 . 40 . 1120

KE = 20 . 1120

KE = 22400 Joules

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Another name for a period is a family?

Zepler [3.9K]

If you are referring to science, then you are correct. A period is also known as a family.

8 0

3 years ago

A 3.0kg mass tied to a string

dem82 [27]

Answer:

$\boxed{\sf Tension \ in \ the \ string \ (T) = 3 \ kN}$

Given:

Mass (m) = 3.0 kg

Uniform speed (v) = 20 m/s

Length of string (r) = 40 cm = 0.4 m

To Find:

Tension in the string (T)

Explanation:

Tension (T) is the string will be equal to centripetal force ( $\sf F_c$ ).

$\boxed{ \bold{ T = F_c = \frac{m {v}^{2} }{r} }}$

Substituting value of m, v & r in the equation:

$\sf \implies T = \frac{3 \times {20}^{2} }{0.4} \\ \\ \sf \implies T = \frac{3 \times 400}{0.4} \\ \\ \sf \implies T =3 \times 1000 \\ \\ \sf \implies T =3000 \: N \\ \\ \sf \implies T =3 \: kN$

$\therefore$

Tension in the string (T) = 3 kN

5 0

3 years ago

The earth's radius is 6.37×106m; it rotates once every 24 hours. What is the earth's angular speed? What is the speed of a point

Zarrin [17]

Answer:

a) w = 7.27 * 10^-5 rad/s

b) v1 = 463.1 m/s

c) v1 = 440.433 m/s

Explanation:

Given:-

- The radius of the earth, R = 6.37 * 10 ^6 m

- The time period for 1 revolution T = 24 hrs

Find:

What is the earth's angular speed?

What is the speed of a point on the equator?

What is the speed of a point on the earth's surface located at 1/5 of the length of the arc between the equator and the pole, measured from equator?

Solution:

- The angular speed w of the earth can be related with the Time period T of the earth revolution by:

w = 2π / T

w = 2π / 24*3600

w = 7.27 * 10^-5 rad/s

- The speed of the point on the equator v1 can be determined from the linear and rotational motion kinematic relation.

v1 = R*w

v1 = (6.37 * 10 ^6)*(7.27 * 10^-5)

v1 = 463.1 m/s

- The angle θ subtended by a point on earth's surface 1/5 th between the equator and the pole wrt equator is.

π/2 ........... s

x ............ 1/5 s

x = π/2*5 = 18°

- The radius of the earth R' at point where θ = 18° from the equator is:

R' = R*cos(18)

R' = (6.37 * 10 ^6)*cos(18)

R' = 6058230.0088 m

- The speed of the point where θ = 18° from the equator v2 can be determined from the linear and rotational motion kinematic relation.

v2 = R'*w

v2 = (6058230.0088)*(7.27 * 10^-5)

v2 = 440.433 m/s

5 0

3 years ago

A 0.46-kg cord is stretched between two supports, 7.2 m apart. When one support is struck by a hammer, a transverse wave travels

Kryger [21]

Answer:

T = 6.0 N

Explanation:

given,

mass of the cord = 0.46 Kg

length of the supports = 7.2 m

time taken to travel = 0.74 s

tension in the chord = ?

using formula for tension calculation

$T = \dfrac{v^2.m}{l}$

$v = \dfrac{l}{s}$

$v = \dfrac{7.2}{0.74}$

v = 9.73 m/s

now, calculation of tension

$T = \dfrac{9.73^2\times 0.46}{7.2}$

T = 6.0 N

The tension in the cord is equal to 6.0 N.

7 0

2 years ago

A series circuit is composed of two resistors:

WITCHER [35]

<h3>Answer:</h3>

1.3 Amps

<h3>Explanation:</h3>

<u>We are given;</u>

A circuit with resistors, R1 and R2

R1 = 7 Ω

R2 = 11 Ω

Voltage = 24 V

We are required to calculate the current in the circuit.

<h3>Step 1: We need to find the effective resistance.</h3>

When resistors are arranged in series, the effective resistance is calculated by;

Rt = R₁ + R₂ + R₃ + ..........Rₙ

Therefore;

Total resistance = 7 + 11

= 18 Ω

<h3>Step 2: Calculate the current in the circuit</h3>

From the ohm's law;

V = IR

Rearranging the formula;

I = V/R

Thus;

I = 24 V ÷ 18 Ω

= 1.333 Amps

= 1.3 Amps

Thus, the current in the circuit is 1.3 Amps

7 0

3 years ago