<span> The boiling point of water at sea level is 100 °C. At higher altitudes, the boiling point of water will be.....
a) higher, because the altitude is greater.
b) lower, because temperatures are lower.
c) the same, because water always boils at 100 °C.
d) higher, because there are fewer water molecules in the air.
==> e) lower, because the atmospheric pressure is lower.
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Water boils at a lower temperature on top of a mountain because there is less air pressure on the molecules.
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I hope this is helpful. </span>
Answer:E
Explanation:
It is given that Energy of gamma ray is E=1.2 Mev
Shielding effect can be measured by measuring the fraction of gamma rays blocked by shield. If certain thickness will able to block half the radiation then to block 75% radiation we need to add same amount of thickness in order to block the remaining radiation.
i.e. 
fraction is blocked by 10 cm thickness
then remaining radiation is
another 10 cm thickness will block the remaining half radiation i.e. 
so total 75 % radiation will be blocked
The acceleration of gravity on or near the surface of the Earth is 9.8 m/s².
Anything acted on only by gravity loses 9.8 m/s of upward speed, or gains
9.8 m/s of downward speed, every second.
Leaping straight upward at 1.8 m/s, Tina keeps rising until she runs out of
upward speed. That happens in (1.8/9.8) = 0.1837 second after the leap.
After that, Finkel's First Law of Motion takes over:
"What goes up must come down."
The dropping part of the leap is symmetrical with the first. Please don't
make me go through proving it. Tina hits the floor at the same speed of
1.8 m/s with which she left it, and it takes the same amount of time to drop
from the peak to the floor as it took to rise from the floor to the peak.
So her total time out of contact with the floor is
2 x (0.1837 sec) = 0.367 second (rounded)
Answer:
Explanation:
Unbalanced Force according to newton's second law is the one which causes the object to move or break its state of rest on application of force.
Here the object accelerate to a speed of 4 m/s and moves a distance of 5 m on application of force .
Thus we can say that the applied force is unbalanced in nature.
Answer:
Explanation:
The impulse-momentum theorem gives the impulse on an object to be equal to the change in momentum of that object. Since mass is maintained, the change in momentum of the basketball is:
, where 
is the mass of the basketball and 
is the change in velocity.
Since the basketball is changing direction, its total change in velocity is:
.
Therefore, the basketball's change in momentum is:
.
Thus, the impulse on the basketball is 
(two significant figures).
