Answer: You do not specify what is being asked for. ∆E? ∆H?
∆E = (430 - 238) J = 192 J
∆H = 430 J
Explanation:
If asked for the value of ∆H the answer is simply the change in heat, and in the question, it states introduction of 430 J of heat is causing the system to expand.
Therefore ∆H = 430 J
If asked for ∆E, we know that ∆E = ±q (heat) + work (-P∆V) = ±q + w
The question states that 238 J of work are done AND the system expanded
(work is negative because expansion means work is done BY the system, releasing energy/heat... Conversely, if the system were compressed, work is done ON the system, absorbing heat/energy)
Therefore, ∆E = (430 - 238) J = 192 J
Answer:
169.74 N
Explanation:
Given,
Mass of the girl = 30 Kg
angle of the rope with vertical, θ = 30°
equating the vertical component of the tension
vertical component of the tension is equal to the weight of the girl.
T cos θ = m g
T cos 30° = 30 x 9.8
T = 339.48 N
Tension on the two ropes is equal to 339.48 N
Tension in each of the rope = T/2
= 339.48/2 = 169.74 N
Hence, the tension in each of the rope is equal to 169.74 N
Answer:
Time period, 
Explanation:
Given that,
The quartz crystal used in an electric watch vibrates with a frequency of 32,768 Hz, f = 32768 Hz
We need to find the period of the crystal's motion. The relationship between the frequency and the time period is given by :
T is the time period of the crystal's motion.
Time period is given by :
So, the time period of the crystal's motion is 
. Hence, this is the required solution.
Answer:
v = 5.15 m/s
Explanation:
At constant velocity, the cable tension will equal the car weight of 984(9.81) = 9,653 N
As the cable tension is less than this value, the car must be accelerating downward.
7730 = 984(9.81 - a)
a = 1.95 m/s²
kinematic equations s = ut + ½at² and v = u + at
-5.00 = u(4.00) + ½(-1.95)4.00²
u = 2.65 m/s the car's initial velocity was upward at 2.65 m/s
v = 2.65 + (-1.95)(4.00)
v = -5.15 m/s
