Answer:
What happens to the pressure of the air inside a sport ball when it is heated?
Explanation:
We can answer this question by thinking at what happen at microscopic level.
In fact, when the gas inside the ball is heated, the molecules of the gas start moving faster. As a result, the rate of collision of the molecules against the internal surface of the ball increases: and therefore, the pressure of the gas inside the ball increases.
We can also see this by looking at the ideal gas law, which states that:
where
p is the gas pressure
V is the gas volume
n is the number of moles
R is the gas constant
T is the absolute temperature of the gas
In this situation, the volume of the gas V is constant (since the ball has a constant volume), the number of moles n is also constant, as well as R. So we can rewrite this as
so we see that the pressure is directly proportional to the temperature: therefore, when the ball is heated, the pressure inside the ball increases.
Answer:
10.93m/s with the assumption that the water in the lake is still (the water has a speed of zero)
Explanation:
The velocity of the fish relative to the water when it hits the water surface is equal to the resultant velocity between the fish and the water when it hits it.
The fish drops on the water surface vertically with a vertical velocity v. Nothing was said about the velocity of the water, hence we can safely assume that the velocity if the water in the lake is zero, meaning that it is still. Therefore the relative velocity becomes equal to the velocity v with which the fish strikes the water surface.
We use the first equation of motion for a free-falling body to obtain v as follows;
v = u + gt....................(1)
where g is acceleration due to gravity taken as 9.8m/s/s
It should also be noted that the horizontal and vertical components of the motion are independent of each other, hence we take u = 0 as the fish falls vertically.
To obtain t, we use the second equation of motion as stated;
Given; h = 6.10m.
since u = 0 for the vertical motion; equation (2) can be written as follows;
substituting;
Putting this value of t in equation (1) we obtain the following;
v = 0 + 9.8*1.12
v = 10.93m/s
Answer:
Honda won by 0.14 s
Explanation:
We are given that
Distance =S=200 m
Initial velocity of Honda=u=0m/s
Initial velocity of Porsche=u'=0m/s
Acceleration of Honda=
Acceleration of Porsche's=
Time taken by Honda to start=1 s
Substitute the values
Time taken by Honda=11.55 s
Now, time taken by Porsche
Total time taken by Porsche=10.69+1=11.69 s
Because it start 1 s late
Time taken by Honda is less than Porsche .Therefore, Honda won and
Time =11.69-11.55=0.14 s
Honda won by 0.14 s
Answer:
C and E...................
Answer:
ωf = 4.53 rad/s
Explanation:
By conservation of the angular momentum:
Ib*ωb = (Ib + Ic)*ωf
Where
Ib is the inertia of the ball
ωb is the initial angular velocity of the ball
Ic is the inertia of the catcher
ωf is the final angular velocity of the system
We need to calculate first Ib, Ic, ωb:
ωb = Vb / (L/2) = 16 / (1.2/2) = 26.67 m/s
Now, ωf will be:
