An object has a coefficient of static friction of 0.3 and a normal force of 30 N. Find the force of static friction.

Answer:

False.

Explanation:

In physics, acceleration can be defined as the rate of change of the velocity of an object with respect to time.

This simply means that, acceleration is given by the subtraction of final speed from the initial speed all over time.

Hence, if we subtract the final speed from the initial speed and divide that by the time, we can calculate an object’s acceleration.

Mathematically, acceleration is given by the equation;

[tex]Acceleration (a) = \frac{initial speed - final speed}{time}[/tex]

[tex]a = \frac{v - u}{t}[/tex]

Where,

a is acceleration measured in [tex]ms^{-2}[/tex]

v and u is initial and final speed respectively, measured in [tex]ms^{-1}[/tex]

t is time measured in seconds.

Additionally, acceleration is a vector quantity because it has both magnitude and direction.

Hence, uniform acceleration means the velocity of the body is increasing at a constant rate. For example, an object or body that is experiencing a free fall in a uniform gravitational field is said to be in uniform acceleration.

Answer:

I think the tone is happiness using the clues of "champion". But depending on who is saying it and background information it could be something different but based on the text here and the answer choices personally the best answer in my opinion is happiness.

If there was jealousy or optimism it would be a harder decision.

Explanation:

Hope this helped :)

Answer:

the runner's average kinetic energy during the run is 476.96 J.

Explanation:

Given;

mass of the runner, m = 85 kg

distance covered by the runner, d = 42.2 km = 42,200 m

time to complete the race, t = 3 hours 30 mins = (3 x 3600s) + (30 x 60s)

                                                                               = 12,600 s

The speed of the runner, v = d/t

                                          v = 42,200 / 12,600

                                          v = 3.35 m/s

The runner's average kinetic energy during the run is calculated as;

K.E = ¹/₂mv²

K.E = ¹/₂ × 85 × (3.35)²

K.E = 476.96 J

Therefore, the runner's average kinetic energy during the run is 476.96 J.

Answer:

[tex]26852726.19\ \text{N}[/tex]

[tex]57.52^{\circ}[/tex]

Explanation:

r = Radius of circle = 7 m

w = Width of dam = 60 m

h = Height of the dam will be half the radius = [tex]\dfrac{r}{2}[/tex]

A = Area = [tex]rw[/tex]

V = Volume = [tex]w\dfrac{\pi r^2}{4}[/tex]

Horizontal force is given by

[tex]F_x=\rho ghA\\\Rightarrow F_x=1000\times 9.81\times \dfrac{7}{2}\times  7\times 60\\\Rightarrow F_x=14420700\ \text{N}[/tex]

Vertical force is given by

[tex]F_y=\rho gV\\\Rightarrow F_y=1000\times 9.81\times 60\times \dfrac{\pi 7^2}{4}\\\Rightarrow F_y=22651982.59\ \text{N}[/tex]

Resultant force is

[tex]F=\sqrt{F_x^2+F_y^2}\\\Rightarrow F=\sqrt{14420700^2+22651982.59^2}\\\Rightarrow F=26852726.19\ \text{N}[/tex]

The hydrostatic force on the dam is [tex]26852726.19\ \text{N}[/tex].

The direction is given by

[tex]\theta=\tan^{-1}\dfrac{F_y}{F_x}\\\Rightarrow \theta=\tan^{-1}\dfrac{22651982.59}{14420700}\\\Rightarrow \theta=57.52^{\circ}[/tex]

The line of action is [tex]57.52^{\circ}[/tex].

Answer:

is there more?

Explanation:

Answer:

3.53 amps

Explanation:

Given data

Power= 60W

Voltage= 17V

The expression relating current, power, and voltage is

P= IV

substitute

60= I*17

I= 60/17

I= 3.53 amps

Hence the current that flows is 3.53 amps

Answer:

[tex]\boxed {\boxed {\sf 5 \ meters/second}}[/tex]

Explanation:

Speed is equal to distance over time.

[tex]s=\frac{d}{t}[/tex]

The distance is 100 meters and the time is 20 seconds.

[tex]d= 100 \ m \\t= 20 \ s[/tex]

Substitute the values into the formula.

[tex]s=\frac{100 \ m }{20 \ s}[/tex]

Divide.

[tex]s= 5 \ m/s[/tex]

Aman's speed is 5 meters per second.

Answer:

the new current on the wire is 3.64 A.

Explanation:

Given;

first force on the wire, F₁ = 0.026 N

second force on the wire, F₂ = 0.063 N

first current on the wire, I₁ = 1.5 A

second current on the wire, I₂ = ?

The force on a current carrying conductor placed in a magnetic field is given as;

[tex]F = BIL(sin \theta)\\\\[/tex]

F ∝ I

[tex]\frac{F_1}{I_1} = \frac{F_2}{I_2} \\\\I_2 = \frac{F_2I_1}{F_1} \\\\I_2 = \frac{0.063\ \times\ 1.5 }{0.026} \\\\I_2 = 3.64 \ A[/tex]

Therefore, the new current on the wire is 3.64 A.

Answer:

Explanation:

Torque acting on a coil in a magnetic field = MBsinθ where M is magnetic moment , B is magnetic field and θ is inclination of the normal to coil with direction of field.

For maximum torque sinθ = 1

Maximum torque = MB

M = NIA where N is no of turns , I is current and A is area of the coil

Maximum torque = NIAB

As maximum torque is same

N₁I₁A₁B₁ = N₂I₂A₂B₂

N₁ = N₂ , I₁ = I₂

A₁B₁ = A₂B₂

π R₁² B₁ = π R₂² B₂

4.5² x .21 = R₂² x .39

R₂² = 10.9

R₂ = 3.3 cm .

Answer:

1. realizing of arrow

2. kicking of ball

3. punching the punching bag

Answer:

200000 J

Explanation:

From the question given above, the following data were obtained:

Mass (m) of roller coaster = 1000 Kg

Velocity (v) of roller coaster = 20 m/s

Kinetic energy (KE) =?

Kinetic energy is simply defined as the energy possess by an object in motion. Mathematically, it can be expressed as:

KE = ½mv²

Where

KE => is the kinetic energy.

m =>is the mass of the object

V => it the velocity of the object.

With the above formula, we can obtain the kinetic energy of the roller coaster as follow:

Mass (m) of roller coaster = 1000 Kg

Velocity (v) of roller coaster = 20 m/s

Kinetic energy (KE) =?

KE = ½mv²

KE = ½ × 1000 × 20²

KE = 500 × 400

KE = 200000 J

Therefore, the kinetic energy of the roller coaster is 200000 J.