What are used to measure temperature.

A small rock with mass 0.12 kg is fastened to a massless string with length 0.80 m to form a pendulum. The pendulum is swinging

bekas [8.4K]

Answer:

The answers to the question are

(a) 2.1 m/s

(b) 0.83 N

(c) 1.9 N

Explanation:

To solve the question, we list out the varibles

Length, l of string = 0.8 m

mass of rock, m = 0.12 kg

Angle with the verrticakl, θ = 45 °

a) To find the speed of the rock when the string passes through the vertical position we have

From the first law of thermodynamics

Potential energy = kinetic energy

m×g×l×(1-cosθ) = 1/2×m×v²

That is v² = 2×g×l×(1-cosθ)

= 2×9.81×0.8×(1-cos45) = 4.597

or v = √4.597 = 2.1 m/s

(b) The tension in the string when it makes an angle of 45∘ with the vertical is given by

For balance between Tension and mass of rock is gigen by

∑Forces = 0, T - m×g×cosθ = 0

or T = m×g×cosθ = 0.12×9.81×cos45 = 0.83 N

c) The tension in the string as it passes through the vertical

when passing through the vertical we have T - m×g = (m×v²)/r

or T = m×g + (m×v²)/r = mg(1+2(1-cosθ)) =0.981*0.12 (1+ 2(1-cos45)) =1.867 N

= 1.9 N

3 0

3 years ago

Puck 1 is moving 10 m/s to the left and puck 2 is moving 8 m/s to the right. They have the same mass, m.

Julli [10]

Answer:

(a) the total momentum of the system before the collision = -2m kg.m/s.

(b) the total momentum of the system after the collision = -2m kg.m/s.

(c) puck 1's velocity after the collision in component form = (5.44 i, 2.54 j)

Explanation:

Given;

mass of Puck 1 , = m

mass of Puck 2, = m (since they have the same mass m)

initial velocity of Puck 1, u₁ = 10 m/s to the left

initial velocity of Puck 2, u₂ = 8 m/s to the right

Let the rightward direction be positive direction

Let the leftward direction be negative direction

(a) the total momentum of the system before the collision;

P₁ = (initial momentum of Pluck 1) + (initial momentum of Pluck 2)

P₁ = (-mu₁) + mu₂

P₁ = mu₂ - mu₁

P₁ = m(u₂ - u₁)

P₁ = m(8 - 10)

P₁ = -2m kg.m/s

(b) the total momentum of the system after the collision;

Based on the principle of conservation of linear momentum, the total momentum before collision is equal to the total momentum after collision.

Thus, the total momentum of the system after the collision is -2m kg.m/s.

(c) puck 1's velocity after the collision in component form

$v = (v_x, v_y)\\\\v = (vcos \theta , vsin \theta)\\\\v = (6cos 25^0 , 6sin25^0)\\\\v = (5.44i, 2.54j)m/s$

8 0

3 years ago

Three electromagnetic waves travel through a certain point P along an x axis. They are polarized parallel to a y axis, with the

chubhunter [2.5K]

Answer:

$4.846*10^{-5} sin(5*10^{14}t )$

Explanation:

Frequency of each electromagnetic wave is same thus we can interfere them along X axis in Phase diagram.

In phase diagram indicate each wave as vector with amplitude as length and phase difference as angle. (shown in attachment)

Now take component of E2 and E3 amplitude along X direction.

Net amplitude of all E in X direction = $4*10^{-5}$ + cos(45)[ $6*10^{-6}$ + $6*10^{-6}$ ]

⇒ $4.846*10^{-5}$

Final resultant have no change in frequency

So , resultant is $4.846*10^{-5} sin(5*10^{14}t )$

6 0

4 years ago

A 2kg ball is thrown upward with a velocity of 15 m/s what is the kinetic energy of the ball being thrown?

vivado [14]

Kinetic Energy, or K.E is equal to 1/2 times the mass of an object times the velocity squared.

Therefore K.E
$= \frac{1}{2} \times 2 \times {15}^{2}$
which is 225

Energy is expressed in joules (J)
so the K.E of the ball is 225J

Hope this helped

7 0

4 years ago

1. A block with a mass of 5.0 kg is pushed on a frictionless surface by applying a horizontal force of 80.0 N. The block starts

Snezhnost [94]

Answer:

397 j

Explanation:

Because 5.0kg yuh

3 0

2 years ago