Answer:
The focal length is 16.86 cm and the distance of the man if he wants to form an upright image of his chin that is twice the chin's actual size is 8.43 cm.
Explanation:
Given that,
Object distance u=1.54 m =154 cm
Image distance v = 15.2 cm
Magnification = 2
We need to calculate the focal length
Using formula of mirror
Put the value into the formula
We need to calculate the focal length
Using formula of magnification
Put the value into the formula
Using formula of for focal length
Hence, The focal length is 16.86 cm and the distance of the man if he wants to form an upright image of his chin that is twice the chin's actual size is 8.43 cm.
Answer:
25104 J
Explanation:
We are given;
Mass; m = 600 g
Change in temperature;Δt = (40 - 30) = 10°C
Specific heat of water; c = 4.184 J/g°C
Now, to find how many joules, we simply use the formula for quantity of heat.
Thus;
Q = mcΔt
Plugging in the relevant values to give;
Q = 600 × 4.184 × 10
Q = 25104 J
Quantity of heat = 25104 J
Answer:592 kJ
Explanation:
Given
mass of elevator m=1500 kg
Lifting height=40 m
Friction Force F=100 N
The cable has to work against gravitational force and friction Force
Increase in Potential Energy of Elevator
thus work done by gravitational force
Work done against friction force
Total Work done by the cable
Answer:
The mass of the feather would be 0.0075 kg.
Explanation:
If the feather were to be on earth, it would have experienced the gravitational pull of the earth downwards. So that from Newton's second law of motion,
F = mg
where f is the force on the object, m is the mass of the object and g is the acceleration due to gravity of the earth.
But, F = 0.075 N, g = 10 m/.
So that,
0.075 = m x 10
m =
= 0.0075 kg
The mass of the feather would be 0.0075 kg.