Answer:
a = 1 m/s² and
Explanation:
The first two parts can be seen in attachment
We use Newton's second law on each axis
Y axis
Ty - W = 0
Ty = w
X axis
Tx = m a
With trigonometry we find the components of tension
Sin θ = Ty / T
Ty = T sin θ
Cos θ = Tx / T
Tx = T cos θ
We calculate the acceleration with kinematics
Vf = Vo + a t
a = (Vf -Vo) / t
a = (20 -10) / 10
a = 1 m/s²
We substitute in Newton's equations
T Sin θ = mg
T cos θ = ma
We divide the two equations
Tan θ = g / a
θ = tan⁻¹ (g / a)
θ = tan⁻¹ (9.8 / 1)
θ = 84º
We see that in the expression of the angle the mass does not appear therefore you should not change the angle
The answer for the question is c
Answer:
(a) 1320 W
(b) 480 W
(c) E':E ≈ 11:2
Explanation:
(a) Applying,
P' = VI'................. Equation 1
Where P' = Power of the blow-dryer, V = Voltage, I = current rating of the blow-dryer.
From the question,
Given: V = 120 V, I' = 11 A
Substitute these values into equation 1
P = (120×11)
P = 1320 W
(b) Similarly,
P = VI................... Equation 2
Where P = Power of the vacuum cleaner. I = current rating of the vacuum cleaner.
Also Given: I = 4 A,
Therefore
P = 4(120)
P = 480 W
(c)
E' = P'/t'............. Equation 3
E = P/t................ Equation 4
Where E' = Energy of the blow-dryer, t' = time of use of the blow-dryer, E = Energy of the vacuum cleaner, t = time of use of the vacuum cleaner
From the question,
Given: t' = 15 minutes = (15×60) = 900 seconds, t = 30 minutes = (30×60) = 1800 seconds
Substitute these values into equation 3 and 4
E' = 1320/900
E' = 1.47 J,
E = 480/1800
E = 0.267
Therefore,
E':E = 1.47:0.267
E':E ≈ 11:2
Answer: 20 newtons
Explanation:
Given that:
Force applied by Samantha = 10 newtons
Force applied by Emily = 10 newtons
Direction of both forces = same
Net force of their efforts = ?
Since net force of forces applied in the same direction is obtained by adding up the seperate forces applied, then
Net force = (10 newtons + 10 newtons)
Net force = 20 newtons
Thus, the net force of their efforts is 20 newtons.
