Answer:
Speed, u = 29.4 m/s
Explanation:
Given that, A ball thrown straight up climbs for 3.0 sec before falling, t = 3 s
Let u is speed with which the ball is thrown up. When the ball falls, v = 0
Using first equation of motion as :
v = u + at
Here, a = -g
So, u = g × t
u = 29.4 m/s
So, the speed with which the ball was thrown is 29.4 m/s. Hence, this is the required solution.
Answer: B. 16
Explanation:
The given table:
x y
2.5 6.25
9.4 88.36
15.6 243.63
19.5 380.25
25.8 665.64
Here, we observed that value of y is the square value of x.
i.e. 
[For example 2.5²=6.25, 9.4²=88.36, 15.6²=243.63]
Put x=4, we get
Hence, the approximate value of y for x = 4 is 16.
So, the correct option is B. 16 .
At constant temperature and volume the pressure of a gas is directly proportional to the number of moles of the gas. PV =n RT, where R is the universal gas constant. A change in pressure depends with the number of moles of the gas, such that if the number of moles increases then there are many vibrations and collision of the gas molecules with the walls of a container thus increasing the pressure and vice versa.
An unstable isotope changes until it reaches a different element that is stable.
An unstable isotope changes until it reaches a different isotope of the same element that is stable.
i just did this on ed the other answer was wrong. these ones are right tho
