Answer:
Because the mechanical advantage of the machine is affected by friction and weight but velocity ratio is not. So, mechanical advantage is less than velocity rate. Thus, the machine's efficiency is less than 100% and can't be a perfect machine
Answer:
Height as seen by the professor = 38.2 m
Explanation:
Angle of throw = θ = 69°
Velocity of throw = v
X component of velocity = v₁ = v cos 69 = 0.3584 v m/s
Vertical component of the velocity = v₂ = v sin 69 = 0.9336 v m/s
v₂ / v₁ = tan 69 = 2.605
v₂ = 2.605 v₁.
Professor sees as if the x component of velocity =0
v (as seen by professor) + v' = 0
=> v as seen by professor = -v' = -10.5 m/s
This shows that y component of the ball's velocity is 2.605 times its x component of velocity.
with respect to the professor, there is only y component of velocity.
v₂' =v₂ = 2.605 ( -10.5) = 27.4 m/s.
Height as seen by the professor = (27.4)² / 2(9.8) = 38.2 m
By Newton's second law, we have

So, in order to give a 0.15kg body an acceleration of 40m/s^2, you need a force of

The magnitude of other charge will be 1 × 10⁻² coulomb
The formula of electrostatic force is
Electrostatic force = K q1 q1 / r²
where k is the coulomb's constant whose value is 9 × 10⁹
q1 and a2 are the magnitude of charges
and r is the distance between them
magnitude of the force given to us is 9.0 × 10⁻⁵ newtons
magnitude of one charge = 1.0 × 10⁻⁶ coulomb
Force = K q1 q2 / r²
9.0 × 10⁻⁵ = ( ( 9 × 10⁹ ) × ( 1.0 × 10⁻⁶ ) × q2 ) / 1
9.0 × 10⁻⁵ = 9 × 10³ × q2
10⁻² = q2
Charge on q2 is 1 × 10⁻² coulomb
So the magnitude of the second charge is came out to be 1 × 10⁻² coulomb after applying the formula of electrostatic force.
Learn more about electrostatic force here:
brainly.com/question/17692887
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