Since heat here is conserved that means that the heat out is equal to the heat in. We use the expression Q = mC(T2-T1). We caclulate as follows:
Q absorbed = Q released
m1 C (T-T1) = -m2 C (T-T1)
C can be cancelled since they are the same substance.
m1 (T-T1) = -m2 (T-T1)
25 (T-10) = -12 (T-30)
T = 16.49 degrees Celsius
Answer:
B will take 1.034 times the time of A from Boston to Hartford.
Explanation:
Let the distance from Boston to Hartford be S.
Person A drives at a constant speed of 55 mph for the entire trip,
Time taken by person A

Person B drives at 65 mph for half the distance and then drives 45 mph for the second half of the distance.
Time taken by person B

Ratio of time of arrival of B to A

B will take 1.034 times the time of A from Boston to Hartford.
Answer:
The value of the linear coefficient of thermal expansion is : α=1.01 *10⁻⁵ (ºC)⁻¹
Explanation:
Li = 0.2m
ΔL = 0.2 mm = 0.0002m
T1 = 21ºC
T2 = 120ºC
ΔT =99ºC
α =ΔL/(Li*ΔT)
α =0.0002m /(0.2m * 99ºC)
α = 1.01 *10⁻⁵ (ºC)⁻¹
Answer:

Explanation:
Given that
J(r) = Br
We know that area of small element
dA = 2 π dr
I = J A
dI = J dA
Now by putting the values
dI = B r . 2 π dr
dI= 2π Br² dr
Now by integrating above equation


Given that
B= 2.35 x 10⁵ A/m³
r₁ = 2 mm
r₂ = 2+ 0.0115 mm
r₂ = 2.0115 mm

By putting the values


Answer:

Explanation:
Mass of the ship (m) = 6.9 × 10⁷ kg
Speed of the ship (v) = 33 km/h
First, let us convert the speed from km/h to m/s using the conversion factor.
We know that, 1 km/h = 5/18 m/s
So, 33 km/h = 
Now, we know, the momentum of an object only depends on its mass and speed. Momentum is independent of the length of the object.
So, here, length of the ship doesn't play any role in the determination of the momentum.
Magnitude of momentum of the ship = Mass × Speed
= 
= 
Therefore, the magnitude of ship's momentum is
.