Answer:
It has very high density, so a small bulb of a thermometer can contain much mercury. Mercury remains liquid state over a quite wide range of temperature because it freezes at 39°C and boils at 357°C.
Explanation:
True
In fact, the weight of an object on the surface of the Earth is given by:
where m is the mass of the object and
is the gravitational acceleration on Earth's surface. If we use the mass of the object, m=3.0 kg, we find
Answer:
2633.7 s
Explanation:
From the question,
Heat lost by the water heater = Heat gained by the water
Applying,
P = cm(t₂-t₁)/t.................. Equation 1
Where P = power of the heat, c = specific heat capacity of water, m = mass of water, t₁ = initial temperature, t₂ = final temperature, t = time
make t the subject of the equation
t = cm(t₂-t₁)/P.............. Equation 2
From the question,
Given: c = 4190 J/kgK, P = 3.5 kW = 3500 W, m = 40 kg, t₁ = 20°C, t₂ = 75°C
Substitute these values into equation 2
t = 4190×40(75-20)/3500
t = 9218000/3500
t = 2633.7 s
When a car travelling at an initial velocity of 10 m/s applies the brakes and bring ... accelerates from rest for a time of 8 seconds with an acceleration of 3.2m/s^2?
Answer:
real, and then virtual
Explanation:
A converging lens is known as convex lens. This lens is called converging lens because it converges all light rays incident on the lens and parallel to the principal axis at the focus.
The nature of image formed by objects placed in front of this lens as mostly REAL IMAGES. The image formed becomes virtual only when the object is almost in close contact with the lens.
Based on the explanation, it can be deduced that an object placed far from a convex lens forms real images but as we move closer to the lens (almost touching the lens), the image formed overtime tends to be virtual.
