Answer: True
Explanation:
Participating in team sports can lead to the development of healthy fellowship and brotherhood behavior among the participants. It induces team spirit and allows to lead a healthy competition. It can be a good recreational activity which can be used for removing the emotional and physiological stress. Hence, can improve positivity in all aspects of life.
Given that,
Frequency emitted by the bat, f = 47.6 kHz
The speed off sound in air, v = 413 m/s
We need to find the wavelength detected by the bat. The speed of a wave is given by formula as follows :

or

So, the bat can detect small objects such as an insect whose size is approximately equal to the wavelength of the sound the bat makes i.e. 8.67 mm.
Answer:
0.0321 g
Explanation:
Let helium specific heat 
Assuming no energy is lost in the process, by the law of energy conservation we can state that the 20J work done is from the heat transfer to heat it up from 273K to 393K, which is a difference of ΔT = 393 - 273 = 120 K. We have the following heat transfer equation:

where
is the mass of helium, which we are looking for:

Work= Force in the direction of displacement*displacement.
You know the force in the direction of displacement (horizontally) and the displacement. So,
W=130*11=1430
Therefore, the work done is 1,430 Joules