Answer:
Explanation:
We know that speed is given by dividing distance by time or multiplying length and frequency. The speed of the father will be given by Lf where L is the length of the father’s leg ad f is the frequency.
We know that frequency of simple pendulum follows that 
Now, the speed of the father will be 
while for the child the speed will be 
The ratio of the father’s speed to the child’s speed will be
Answer:
120 m
Explanation:
Given:
wavelength 'λ' = 2.4m
pulse width 'τ'= 100T ('T' is the time of one oscillation)
The below inequality express the range of distances to an object that radar can detect
τc/2 < x < Tc/2 ---->eq(1)
Where, τc/2 is the shortest distance
First we'll calculate Frequency 'f' in order to determine time of one oscillation 'T'
f = c/λ (c= speed of light i.e 3 x 
m/s)
f= 3 x / 2.4
f=1.25 x hz.
As, T= 1/f
time of one oscillation T= 1/1.25 x
T= 8 x 
s
It was given that pulse width 'τ'= 100T
τ= 100 x 8 x => 800 x s
From eq(1), we can conclude that the shortest distance to an object that this radar can detect:
= τc/2 => (800 x x 3 x )/2
=120m
Answer:
Temperature decreases because the number of collision of the molecules decreases as they escape or evaporate. Molecules are in constant motion. Increase in temperature leads to increase in average kinetic energy of the molecules.
Answer:
Answer 3: When a balloon goes up higher in the air, its size will increase. Since there's less air in the upper atmosphere, there's less stuff pushing back on the balloon, and hence the pressure is lower, which allows the balloon to expand
Answer: C
Explanation:
As the balloon rises, the gas inside the balloon expands because the atmospheric pressure surrounding the balloon drops. The atmosphere is 100 to 200 times less dense at the float altitudes than on the ground. and as the air is heated inside the balloon it causes it to rise upwards (because it is lighter than the cooler air on the outside). When the pilot needs to bring the balloon down again, he simply reduces the temperature of the air inside the balloon causing it to slowly descend.
C^2=a^2+b^2
c^2=45^2+45^2
c^2=4050
c=63.64
c=64
The answer is D.
