Select a building material for the walls and floor wood piece, clay block, iron block, Aluminium, copper, nickel

2. Consider a conical pendulum with a bob of mass m = 77.0 kg on a string of length L = 10.0 m that makes an angle of ???? 3.00°

bekas [8.4K]

Explanation:

It is given that,

The mass of bob, m = 77 kg

Length of the string, L = 10 m

Angle made by the string with the vertical, $\theta=3^{\circ}$

(a) Let T is the force exerted by the string on the pendulum. At equilibrium,

$T\ cos\theta=mg$

$T=\dfrac{mg}{cos\theta}$

$T=\dfrac{77\times 9.8}{cos(3)}$

T = 755.63 N

The horizontal component of the force is given by,

$T_H=T\ sin\theta$

$T_H=755.63\ sin(3)=39.54\ N$

The vertical component of the force is given by,

$T_V=T\ sin\theta=mg$

$T_V=754.59\ N$

(b) Let a is the radial acceleration of the bob. It can be calculated as :

$a=\dfrac{T_H}{m}$

$a=\dfrac{39.54\ N}{77\ kg}$

$a=0.51\ m/s^2$

Hence, this is the required solution.

6 0

3 years ago

A 1.70 kg block slides on a horizontal, frictionless surface until it encounters a spring with a force constant of 955 N/m. The

Mariana [72]

Answer:

The initial speed of the block is 1.09 m/s

Explanation:

Given;

mass of block, m = 1.7 kg

force constant of the spring, k = 955 N/m

compression of the spring, x = 4.6 cm = 0.046 m

From principle of conservation of energy

kinetic energy of the block = elastic potential energy of the spring

¹/₂mv² = ¹/₂kx²

mv² = kx²

$v = \sqrt{\frac{kx^2}{m} }$

where;

v is the initial speed of the block

x is the compression of the spring

$v = \sqrt{\frac{955*(0.046)^2}{1.7} } \\\\v = 1.09 \ m/s$

Therefore, the initial speed of the block is 1.09 m/s

4 0

3 years ago

A car drives 90 meters north, then turns around and drives 120 meters south. What was its displacement and distance?

Rufina [12.5K]

Answer:

displacement= 30 m towards south, distance= 210m

Explanation:

Distance (scalar quantity) how much ground an object has covered.

Displacement (vector quantity) refers to how far out of place an object is it is the object's overall change in position.

Basically meaning for displacement the directions will be very key

D for Displacement

D= D1+D2

D= 120 (S) + 90 m (N)

Must be in same direction

D= 120 (S) + (-90 m) (S)

D= 30 m (S)

and for distance you are simply just adding how much distance they have covered

so d= d1+d2

d= 90m + 120m

d= 210m

3 0

3 years ago

An arrow is launched with an initial velocity of 7.6 m/s at an angle of 42 degrees above the horizontal. What is the horizontal

AleksAgata [21]

Explanation:

At any point on the arrow's trajectory, the horizontal component of the velocity is the same. Therefore, the horizontal component of the velocity at the top of its trajectory is

$v_x = v_{0x} = v_0\cos{42°} = (7.6\:\text{m/s})\cos{42°}$

$\:\:\:\:\:=5.6\:\text{m/s}$

5 0

3 years ago

It is not possible to convert work entirely into heat. It is impossible to transfer heat from a cooler to a hotter body. The sec

Irina-Kira [14]

Complete Question:

Which one of the following is a

true statement?

Group of answer choices.

A) The second law of thermodynamics is a consequence of the first law of thermodynamics.

B) It is possible for heat to flow spontaneously from a hot body to a cold one or from a cold one

to a hot one, depending on whether or not the process is reversible or irreversible.

C) It is not possible to convert work entirely into heat.

D) It is impossible to transfer heat from a cooler to a hotter body.

E) All of these statements are false.

Answer:

E) All of these statements are false.

Explanation:

All of the following statements are false;

I. The second law of thermodynamics is a consequence of the first law of thermodynamics. The second law of thermodynamics is about a physical quantity known as entropy while the first law of thermodynamics states that energy cannot be created or destroyed but can only be transformed from one form to another.

II. It is possible for heat to flow spontaneously from a hot body to a cold one or from a cold one

to a hot one, depending on whether or not the process is reversible or irreversible. According to the second law of thermodynamics this is false due to the entropy.

III. It is not possible to convert work entirely into heat. It is possible to completely convert work into heat because it involves transferring energy.

IV. It is impossible to transfer heat from a cooler to a hotter body.

6 0

3 years ago