The beats are actually two new sounds.
Their frequencies are (the sum of the original two frequencies) and (the difference of the original two frequencies).
The existence of the beats is the result of the difference in the frequencies of the original two sounds. <em> (b)</em>
Answer:
2.521 (A); 14.0924 (V)
Explanation:
more info in the attachment, the answers are marked with red colour.
Answer:
265 J
Explanation:
where KE is kinetic energy, PE is potential energy, m is the mass of an object, v is the speed, h is the height and g is acceleration due to gravity.
Substituting 19.7 Kg for mass, 0.934 for h, 2.93 for v and 9.81 for g then
The answer is D. The input force is equal to the output force.
I just did test and got it right
Force of gravity on an object is the weight of the object and is given by mass times accerelation due to gravity. The accerelation due to gravity is the accerelation of an object in free fall and is given by 9.8m/s^2. Given that the force of gravity acting on a child's mass on earth is 490 newtns, i.e. F = mg which means that 490 newtons = 9.8 times mass. Therefore, mass of the child is 490 / 9.8 = 50 kg.
