Convex Lenses are used to focus light and form a image. They are transparent.
They are one type of lenses. Different type of lenses are used to focus light differently. The basic lenses are concave and convex. Convex lenses converge light falling on it whereas concave lenses diverge light falling on it.
The air pressure inside the balloon increases as the number of particles increases.
Answer:
Options d and e
Explanation:
The pendulum which will be set in motion are those which their natural frequency is equal to the frequency of oscillation of the beam.
We can get the length of the pendulums likely to oscillate with the formula;

where g=9.8m/s
ω= 2rad/s to 4rad/sec
when ω= 2rad/sec

L = 2.45m
when ω= 4rad/sec

L = 9.8/16
L=0.6125m
L is between 0.6125m and 2.45m.
This means only pendulum lengths in this range will oscillate.Therefore pendulums with length 0.8m and 1.2m will be strongly set in motion.
Have a great day ahead
Answer:
0.34 sec
Explanation:
Low point of spring ( length of stretched spring ) = 5.8 cm
midpoint of spring = 5.8 / 2 = 2.9 cm
Determine the oscillation period
at equilibrum condition
Kx = Mg
g= 9.8 m/s^2
x = 2.9 * 10^-2 m
k / m = 9.8 / ( 2.9 * 10^-2 ) = 337.93
note : w =
=
= 18.38 rad/sec
Period of oscillation = 
= 0.34 sec
Here I come and we wanna go home!!!