Answer
t = 367.77 s = 6.13 min
Explanation:
According to the law of conservation of energy:
where,
P = Electric Power of Heater = 300 W
t = time required = ?
m_g = mass of glass = 300 g = 0.3 kg
m_w = mass of water = 250 g = 0.25 kg
C_g = speicific heat of glass = 840 J/kg.°C
C_w = specific heatof water = 4184 J/kg.°C
ΔT_g = ΔT_w = Change in Temperature of Glass and water = 100°C - 15°C
ΔT_g = ΔT_w = 85°C
Therefore,
<u>t = 367.77 s = 6.13 min</u>
Answer:
option E
Explanation:
given,
diameter = 4 mm
shutter speed = 1/1000 s
diameter of aperture = ?
shutter speed = 1/250 s
exposure time to the shutter time
N is the diameter of the aperture and t is the time of exposure
now,
inserting all the values
N₂² = 4
N₂ = 2 mm
hence , the correct answer is option E
Answer:
a= 0.22 m/s²
Explanation:
Given that
M = 3.5 kg
θ = 30°
m = 1 kg
μ= 0.3
The force due to gravity
F₁= M g sinθ
F₁=3.5 x 10 x sin 30
F₁= 17.5 N
F₂ = m g
F₂ = 1 x 10 = 10 N
The maximum value of the friction force on the incline plane
Fr = μ M g cosθ
Fr = 0.3 x 2.5 x 10 cos30°
Fr= 6.49 N
Lets take acceleration of the system is a m/s²
F₁ - F₂ - Fr = (M+m) a
17.5 - 10 - 6.49 = (3.5+1)a
a= 0.22 m/s²
