Efficiency of a simple machine is the ratio of mechanical advantage and speed ratio.

If mechanical advantage = speed ratio then efficiency = 1
Which is impossible for a practical machine due to presence of frictional force which wastes some energy and thus lowers the output

6 0

3 years ago

La corriente en un circuito se triplica conectando una R1 = 500 Ω en paralelo con la resistencia R del circuito. Determinar R en

Alexxx [7]

Answer:

R = 1000 ohm

Explanation:

In a circuit with a resistor R, the current is

V = i R

i₀ = V / R

a resistor R₁ is placed in parallel and the current is tripled i = 3 i₀

V = i Req

i = V / Req

3i₀ = V / Req

we substitute

3 (V / R) = V / Req

3 / R = 1 / Req

R = 3 Req

the equivalent resistance of the two resistors in parallel is

$\frac{1}{R_{eq}} = \frac{1}{R} + \frac{1}{R_1}$ $\frac{1}{R_{eq}} = \frac{R_1 + R}{R \ R_1}$

R_{eq} = $\frac{R \ R_1}{R + R_1}$

R / 3 = \frac{R \ R_1}{R + R_1}

⅓ (R₁ + R) = R₁

R = 3R₁ -R₁ = 2 R₁

R = 2 500

R = 1000 ohm

4 0

3 years ago

1. The head of a rattlesnake can accelerate 50.00 m/s2 in striking a victim. If a car

scoray [572]

Answer:

2.000 s

Explanation:

Given:

a = 50.00 m/s²

v = 100.0 m/s

v₀ = 0 m/s

Find: t

v = at + v₀

(100.0 m/s) = (50.00 m/s²) t + (0 m/s)

t = 2.000 s

3 0

3 years ago