This is my exam question be serious

A tire measures 20 inches in diameter. How many revolutions will the tire have completed when it has traveled 100 yards? Express

Soloha48 [4]

<h2>Number of revolutions required to travel 100 yards is 57.</h2>

Explanation:

Diameter of tire,D = 20 inches

Perimeter of tire = πD

Perimeter of tire = π x 20 = 62.8 inches

Distance traveled = 100 yards

1 yard = 36 inches

Distance traveled = 100 x 36 = 3600 inches

In one revolution it travels 62.8 inches.

$\texttt{No of revolutions = }\frac{3600}{62.8}\\\\\texttt{No of revolutions = }57.32\\\\\texttt{No of revolutions = }57$

Number of revolutions required to travel 100 yards is 57.

8 0

3 years ago

A small sphere is hung by a string from the ceiling of a van. When the van is stationary, the sphere hangs vertically. However,

Paraphin [41]

Answer: 42.49 $m/s^{2}$

Explanation:

To solve this, we need to keep in mind the following:

While the sphere hangs it is under the effect of gravity. It is creating a Angle of 90° taking the roof as a reference.

Gravity can be noted as a Acceleration Vector. The magnitud for Earth's Gravity is a constant: 9.81 $m/s^{2}$

The acceleration of the Van will affect the sphere also, but this accelaration will be on the X-axis and perpendicular to the gravity. Because this two vectors are taking action under the sphere they will create a angle. This angle can be measured as a relation of the two magnitudes.

Tangent (∅) = Opossite Side / Adyacent Side

By trigonometry, we know the previous formula. This formula allows us to find the Tangent of a angle as a relation between the two perpendiculars magnitudes. In this case the Opossite Side will be the Gravity Accelaration, while the Adyancent Side is the Van's Acceleration.

(1) Tangent (∅) = Gravity's Acceleration (G) / Van's Acceleration (Va)

Searching for the Va in (1)

Va = G/Tan(∅)

Where ∅ in this case is equal to 13.0°

Va = 9.81 $m/s^{2}$ / Tan(13.0°)

Va = 42.49 $m/s^{2}$

The vans acceleration need to be 42.49 $m/s^{2}$ to create an angle of 13° with the Van's Roof

3 0

3 years ago

Is baking a cake conduction, convection, or radiation?

Stolb23 [73]

Answer:

baking- is a method of cooking food that uses prolonged dry heat, normally in an oven, but also in hot ashes, or on hot stones. The primary source of heat is radiation. Fans within the oven will increase cooking times via convection of the air.

5 0

2 years ago

A 1.4-kg cart is attached to a horizontal spring for which the spring constant is 50 N/m . The system is set in motion when the

marin [14]

Answer:

A)

0.395 m

B)

2.4 m/s

Explanation:

A)

$m$ = mass of the cart = 1.4 kg

$k$ = spring constant of the spring = 50 Nm⁻¹

$x$ = initial position of spring from equilibrium position = 0.21 m

$v_{i}$ = initial speed of the cart = 2.0 ms⁻¹

$A$ = amplitude of the oscillation = ?

Using conservation of energy

Final spring energy = initial kinetic energy + initial spring energy

$(0.5) kA^{2} = (0.5) m v_{i}^{2} + (0.5) k x_{i}^{2} \\kA^{2} = m v_{i}^{2} + k x_{i}^{2} \\(50) A^{2} = (1.4) (2.0)^{2} + (50) (0.21)^{2} \\A = 0.395 m$