Answer:195 J
Explanation:
Given
mass of ball 
ball leaves the hand with 
maximum height reached by ball 
Initial Mechanical energy when ball just leaves the hand
considering hand to be datum so h_1=0[/tex]
so Potential energy at ground is zero
Mechanical Energy at highest point
at highest Point velocity is zero
Decrease in Mechanical energy
Answer: the pair of sunglasses
Explanation:
A good pair of sunglasses are composed of abosorbent lenses that filter the sunlight that affects the eyes retina, especially ultraviolet (UV). So, these sunglasses are used to reduce the amount of light or radiant energy transmitted.
On the other hand, normal reading glasses (in which the lens glass has not been treated to filter ultraviolet sunlight) will let UV rays pass through.
Therefore, if both glasses are exposed to sunlight, the sunglasses are expected to be warmer by absorbing that radiant energy and preventing it from reaching the eyes.
Answer:
Maximum height the atmosphere pressure can support the
water=10.336 m
Explanation:
We know that ,
Case 1 - Mercury in the tube
Case 2 - Water in the tube
Since atmospheric pressure is same
.
or, 
∴ 
Hence height of the water column =10.336 m
Answer:
This is because below 4°c, water unlike other materials becomes less dense when it's temperature is further lowered.
Explanation:
Due to the unusual nature of water; at about 4°c, the behavior of the density of water in relation to its temperature reverses. This means that water becomes less dense as it becomes colder below 4°c. The colder parts therefore floats to the top of the water body while the warmer part sinks allowing the top to freeze and the remaining body below to remain in its liquid state.
The freezing of the top of the lake alone protects the remaining depth of water from freezing by acting as an insulator and preventing further heat loss from the water to the ambient space. If this had not been the case, and water froze all through, marine lives will freeze to death and it will be more difficult to melt the ice come the next summer.
This behavior is due to the hydrogen bonding of the water molecules.
