Answer:
31.2 m/s
Explanation:
= Frequency of approach = 480 Hz
= Frequency of going away = 400 Hz
= Speed of sound in air = 343 m/s
= Speed of truck
Frequency of approach is given as
eq-1
Frequency of moving awayy is given as
eq-2
Dividing eq-1 by eq-2


= 31.2 m/s
Answer:

Explanation:
From the question we are told that:
Radius 
Charge Density 
Distance
Generally the equation for electric field is mathematically given by



Answer:
(a) An electric iron works on the heating effect of electric current
(b) The heating effect of an electric current is the tendency for electric current to cause the temperature of the material through which it is flowing to rise due to the resistance of the material
The heating effect, 'E', is given by the formula, E = I²·R·t
Where;
I = The current flowing
R = The resistance of the material
t = The time the material takes to heat up
(c) The values showed by Pinki here is the value of care, concern and prevention, to prevent the harmful effect of the high heat on the skin of her daughter
Explanation:
Answer: I put the importance of the lab in the topic is to find how dense an object is and if it can sink or float and it's important to answer the question so you can also find mass and volume.
Explanation: I dunno haha...