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3 years ago

Find the power of a force F~ = (8 N)ˆı + (−4 N) ˆ if the velocity ~v = (−7 m/s)ˆı + (1 m/s) ˆ. Answer in units of W

Physics

1 answer:

Vikki [24]3 years ago

6 0

Answer:

$P=-60W$

Explanation:

From the question we are told that

Force of power $F=8Ni+-4Nj$

Velocity of power $V=-7m/si+1m/sj$

Generally the equation for power is mathematically represented as

$Power=Force *Velocity$

$P=F *V$

Generally the dot product of F and V is mathematically given as

$P=$ $\begin{vmatrix}8 & -4\end{vmatrix} .$ $\begin{vmatrix}-7 & 1\end{vmatrix}$ $=-56-4$

$P=-60W$

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An automobile steering wheel is shown. What is the ideal mechanical advantage? If the AMA is 8, what is the efficiency of the st

Mars2501 [29]

1. Ideal Mechanical Advantage (IMA): 9

Explanation:

For a wheel and axle system like the steering wheel, the IMA is given by:

$IMA=\frac{r_w}{r_a}$

where

$r_w$ is the radius of the wheel

$r_a$ is the radius of the axle

For the steering wheel of the problem, we see that $r_w = 18 cm$ and $r_a=2 cm$ , so the IMA is

$IMA=\frac{18 cm}{2 cm}=9$

2. Efficiency: 88.9%

Explanation:

The efficiency of a system is defined as the ratio between the AMA (actual mechanical advantage) and the IMA:

$\eta=\frac{AMA}{IMA}\cdot 100$

In this problem, AMA=8 and IMA=9, so the efficiency is

$\eta=\frac{8}{9}\cdot 100=88.9\%$

6 0

3 years ago

A football is place kicked with a velocity having a vertical component of 12 m/s and a horizontal component of 6 m/s. Find the r

SSSSS [86.1K]

The velocity is given by:

V = √(Vx²+Vy²)

V = velocity, Vx = horizontal velocity, Vy = vertical velocity

Given values:

Vx = 6m/s, Vy = 12m/s

Plug in and solve for V:

V = √(6²+12²)

V = 13.42m/s

Now find the direction:

θ = tan⁻¹(Vy/Vx)

θ = angle of velocity off horizontal, Vy = vertical velocity, Vx = horizontal velocity

Given values:

Vx = 6m/s, Vy = 12m/s

Plug in and solve for θ:

θ = tan⁻¹(12/6)

θ = 63.4°

The resultant velocity is 13.42m/s at an angle of 63.4° off the horizontal.

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4 years ago

Find the wavelength λ of the 80.0-khz wave emitted by the bat. express your answer in millimeters.

vfiekz [6]

Answer:

4.29 millimeters

Explanation:

Bats emit ultrasound waves: in air, ultrasound waves travel at a speed of

$v=343 m/s$

The frequency of the waves emitted by this bat is:

$f=80.0 kHz = 80,000 Hz$

Therefore we can find the wavelength of the wave emitted by the bat by using the relationship between speed, frequency and wavelength:

$\lambda=\frac{v}{f}=\frac{343 m/s}{80,000 Hz}=4.29\cdot 10^{-3} m=4.29 mm$

4 0

3 years ago

Two charged objects separated by some distance attract each other. If the charges on both objects are doubled with no change in

Serggg [28]

Answer:

(a) The force between them quadruples

Explanation:

According to coulomb's law, initial force between the two charged objects is given as;

$F_1=\frac{Kq_1q_2}{r^2}$

where;

k is coulomb's constant

q₁ is the charge on the first object

q₂ is the charge on the second object

r is the distance between the two objects

When the charges on both objects are doubled, then;

q₁ = 2q₁

q₂ = 2q₂

Force between the two charged objects will become

$F_2 = \frac{K2q_12q_2}{r^2} = \frac{4Kq_1q_2}{r^2} = 4(\frac{Kq_1q_2}{r^2}) = 4F_1$

Therefore, the force between them quadruples

4 0

3 years ago

As a diligent physics student, you carry out physics experiments at every opportunity. At this opportunity, you carry a 1.33 m l

deff fn [24]

Answer: 62 μT

Explanation:

Given

Length of rod, l = 1.33 m

Velocity of rod, v = 3.19 m/s

Induced emf, e = 0.263*10^-3 V

Using Faraday's law, the induced emf of a rod can be gotten by the formula

e = blv where,

e = induced emf of the rod

b = magnetic field of the rod

l = length of the rod

v = velocity of the rod. On substituting, we have

0.263*10^-3 = b * 1.33 * 3.19

0.263*10^-3 = b * 4.2427

b = 0.263*10^-3 / 4.2427

b = 0.0000620 T

b = 62 μT

Thus, the strength of the magnetic field is 62 μT

8 0

3 years ago

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