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A racing car is travelling at 70 m/s and accelerates at -14 m/s^2. What would the car’s speed be after 3 s?

A racing car is travelling at 70 m/s and accelerates at -14 m/s^2.

- Initial velocity (u) = 70 m/s
- Acceleration (a) = -14 m/s^2
- Time (t) = 3 s
- Let the velocity of the car after 3 s be v m/s
- By using the formula,

v = u + at, we have

- So, the velocity of the car after 3 s is 28 m/s.

The car's speed after 3 s is 28 m/s.

Hope it helps

Hearing the siren of an approaching fire truck, you pull over to side of the road and stop. As the truck approaches, you hear a tone of 460 Hz; as the truck recedes, you hear a tone of 410 Hz. How much time will it take to jet from your position to the fire 5.00 km away, assuming it maintains a constant speed?

If a material has an index of refraction of 1.61, Determine the speed of light through this medium

A 580-mm long tungsten wire, with a 0.046-mm-diameter circular cross section, is wrapped around in the shape of a coil and used as a filament in an incandescent light bulb. When the light bulb is connected to a battery, a current of 0.526 A is measured through the filament. (Note: tungsten has a resistivity of 4.9 × 10-8 Ω • m.). How many electrons pass through this filament in 5 seconds?

A power P is required to do work W in a time interval T. What power is required to do work 3W in a time interval 5T? (a) 3P (b) 5P (c) 3P/5 (a) P (e) 5P/3

An athlete can exercise by making mechanical waves in ropes. What is themedium of these waves?A. EnergyB. The ropeC. The athleteD. Air

If a material has an index of refraction of 1.61, Determine the speed of light through this medium

A 580-mm long tungsten wire, with a 0.046-mm-diameter circular cross section, is wrapped around in the shape of a coil and used as a filament in an incandescent light bulb. When the light bulb is connected to a battery, a current of 0.526 A is measured through the filament. (Note: tungsten has a resistivity of 4.9 × 10-8 Ω • m.). How many electrons pass through this filament in 5 seconds?

A power P is required to do work W in a time interval T. What power is required to do work 3W in a time interval 5T? (a) 3P (b) 5P (c) 3P/5 (a) P (e) 5P/3

An athlete can exercise by making mechanical waves in ropes. What is themedium of these waves?A. EnergyB. The ropeC. The athleteD. Air

**Answer:**

**The speed of the arrow immediately after it leaves the bow is 38.73 m/s**

**Explanation:**

given information:

force, F = 150 N

x = 50 cm = 0.5 m

mass of arrow, m = 50 g = 0.05 kg

We start from the force of the spring

F = kx

k =

=

= 300 N/m

The potential energy, EP of the spring is

EP =

the kinetic energy, EK of the spring

EK =

According to conservative energy,

EP = EK

=

=

=

v =

=

= **38.73 m/s**

Using **Hooke's Law**, we can determine the speed of the arrow. The speed of the arrow immediately after it leaves the bow is approximately 38.7 m/s.

In this problem, we can use Hooke's Law to determine the speed of the arrow. Hooke's Law states that the force exerted by a spring is proportional to the displacement of the spring:

F = -kx

Where F is the force, x is the displacement, and k is the spring constant.

In this case, the force exerted by the bow on the arrow is acting like a spring force. The force of the bow is 150N, and the displacement is 50cm (which is equivalent to 0.5m). So we can set up the equation as:

150N = -k * 0.5m

Now we can solve for k:

k = -150N / 0.5m = -300 N/m

Now that we have the spring constant, we can use it to find the potential energy stored in the bow:

PE = 0.5kx^2 = 0.5*(-300N/m)*(0.5m)^2 = 37.5 J

Next, we can use the conservation of energy to find the kinetic energy of the arrow right after it leaves the bow. The potential energy stored in the bow is converted into kinetic energy:

KE = PE = 37.5 J

The kinetic energy is given by the equation:

KE = 0.5mv^2

Where m is the mass of the arrow and v is its velocity. Rearranging the equation, we can solve for v:

v = sqrt(2KE/m) = sqrt(2*37.5 J / 0.05 kg) = sqrt(1500) m/s ≈ **38.7 m/s**.

#SPJ3

**Answer:**

a) Revolutions per minute = 2.33

b) Centripetal acceleration = 11649.44 m/s²

**Explanation:**

a) Angular velocity is the ratio of linear velocity and radius.

Here linear velocity = 72 m/s

Radius, r = 0.89 x 0. 5 = 0.445 m

Angular velocity

Frequency

Revolutions per minute = 2.33

b) Centripetal acceleration

Here linear velocity = 72 m/s

Radius, r = 0.445 m

Substituting

Centripetal acceleration = 11649.44m/s²

**Answer:**

**6.5e-4 m**

**Explanation:**

We need to solve this question using law of conservation of energy

**Energy at the bottom of the incline= energy at the point where the block will stop**

Therefore,** Energy at the bottom of the incline consists of the potential energy stored in spring and gravitational potential energy=**

**Energy at the point where the block will stop consists of only gravitational potential energy=**

Hence from Energy at the bottom of the incline= energy at the point where the block will stop

⇒

⇒

Also

where is the mass of block

is acceleration due to gravity=9.8 m/s

is the difference in height between two positions

⇒

Given m=2100kg

k=22N/cm=2200N/m

x=11cm=0.11 m

∴

⇒

⇒

**⇒h=0.0006467m=**

**Answer:**

Following are the solution to the given question:

**Explanation:**

Please find the complete question in the attached file.

The cost after 30 days is 60 dollars. As energy remains constant, the cost per hour over 30 days will be decreased.

Thus,

The electricity used is continuously 694W over 30 days.

If just resistor loads (no reagents) were assumed,

Energy usage reduction percentage =

This bulb accounts for of the energy used, hence it saves when you switch it off.

**Answer:**

Solvent

**Explanation:**

- A solution is a substance that is made by dissolving one component in another.
- It is made up of a solvent and a solute.
- The component that dissolves the other is known as solvent. Examples of solvents include water, ethanol, milk, chloroform, etc.
- The component that dissolves in the other is known as the solute. Examples of solute include salts, sugar, etc.
- For example in an aqueous solution of sodium chloride(NaCl); sodium chloride salt is the solute while water is the solvent.

The **linear speed **of the **ball **for the circular motion is determined as** 12 m/s.**

The given parameters;

*mass of each ball, m = 450 g = 0.45 kg**length of the rod, L = 0.2 m**radius of the rod, r = 0.1 m**angular speed of the ball, ω = 120 rad/s*

The **linear speed** of the ball is calculated as follows;

v = ωr

where;

*ω is the angular speed of the ball**r is the radius of circular motion of the ball*

The **linear speed **of the ball is calculated as follows;

v = ωr

v = 120 x 0.1

v = 12 m/s

Thus, the **linear speed **of the **ball **for the circular motion is determined as** 12 m/s.**

Learn more here:brainly.com/question/14404053

**Answer:**

**The speed of ball is 12 **

**Explanation:**

Given:

Mass of ball kg

Radius of rotation m

Angular speed

Here barbell spins around a pivot at its center and barbell consists of two small balls,

**From the formula of speed in terms of angular speed,**

Where speed of ball

**Therefore, the speed of ball is 12 **