Answer:
The wavelength is 0.14 m
Explanation:
Given that,
Frequency = 2450 Hz
Speed of sound = 343 m/s
We need to calculate the wavelength
Using formula of wavelength
Where, v = speed of sound
f = frequency
Put the value into the formula
Hence, The wavelength is 0.14 m
No. It’s moving at a constant speed (speed is not changing) in a straight line (same direction so velocity is not changing) so it is not accelerating. Acceleration only occurs if there’s a change in speed/velocity.
Given that:
Energy of bulb (Work ) = 30 J,
Time (t) = 3 sec
The power consumption = ?
We know that, Power can be defined as rate of doing work
Power (P) = Work(Energy supplied) ÷ time
= 30 ÷ 3
= 10 Watts
<em> The power consumption is 10 W.</em>
Answer:
C. 0 J
Explanation:
When an object moves in a circle, friction provides the centripetal force. Hence, it is acting towards the centre of the circle. The displacement of the object is tangential to the circle at the point of interest. Hence, the angle between the frictional force and the displacement is 90°.
Work done is given by
<em>W</em> = <em>Fd</em> cos <em>θ</em>
where <em>F</em> is the force, <em>d</em> is the displacement and <em>θ</em> is the angle between them.
<em>W</em> = <em>Fd</em> cos 90° = 0 J
Hence, the work done by friction is 0 J.
