Answer:
The focal length of the lens must be 27.3cm
Explanation:
Image distance= -75 cm
Object distance= 20.0cm
From:
1/v + 1/u = 1/f
-1/75+ 1/20 = 1/f
11/300= 1/f
f= 300/11
f= 27.3cm
The focal length of the lens must be 27.3cm
Answer:
It's centripetal acceleration is 301.7 m/s²
Explanation:
The formula to be used here is that of the centripetal acceleration which is
ac = rω²
where ac is the centripetal acceleration = ?
ω is the angular velocity = 3 revolutions per second is to be converted to radian per second: 3 × 2π = 3 × 2 × 3.14 = 18.84 rad/s
r is the radius = 0.85 m
ac = 0.85 × 18.84²
ac = 301.7 m/s²
It's centripetal acceleration is 301.7 m/s²
Answer:
C
Explanation:
Gravity is the main reason that make our planets to pull each other
Answer:
(A) 140 j/sec (b) 1.26 K
Explanation:
We have given the heat heat flowing into the refrigerator = 40 J/sec
Work done = 40 W
(a) So the heat discharged from the refrigerator
(b) Total heat absorbed =140 j/sec
Let the temperature be
Heat absorbed per hour =504000
So
Answer:
Velocity is 2.17 m/s at an angle of 9.03° above X-axis.
Explanation:
Mass of object 1 , m₁ = 300 g = 0.3 kg
Mass of object 2 , m₂ = 400 g = 0.4 kg
Initial velocity of object 1 , v₁ = 5.00i-3.20j m/s
Initial velocity of object 2 , v₂ = 3.00j m/s
Mass of composite = 0.7 kg
We need to find final velocity of composite.
Here momentum is conserved.
Initial momentum = Final momentum
Initial momentum = 0.3 x (5.00i-3.20j) + 0.4 x 3.00j = 1.5 i + 0.24 j kgm/s
Final momentum = 0.7 x v = 0.7v kgm/s
Comparing
1.5 i + 0.24 j = 0.7v
v = 2.14 i + 0.34 j
Magnitude of velocity
Direction,
Velocity is 2.17 m/s at an angle of 9.03° above X-axis.