Answer:
The speed will be "18km/s". A further explanation is given below.
Explanation:
According to the question, the values are:
Wavelength,



As we know,
⇒ 
On substituting the values, we get
⇒ 
⇒ 
⇒ 
⇒ 
or,
⇒ 
Answer:
b) 900 W
Explanation:
The breaker trips when the current is equal to 20 A. The power (P) is the ddp (V) multiplied by the current. So, for the electric heater, the current is:
P = V*i
1500 = 120*i
i = 12.5 A
So, to become in 20 A, it's needed 7.5 A, which must come from the hairdryer. Its power must be:
P = 120*7.5
P = 900 W
Answer:
R=V/I=6/2=3ohm
time =5minutes =5*60=300seconds
I=2A
Heat =I^2Rt=(2)^2*3*300=4*900=3600J
Answer:
Part a)

Part b)

Explanation:
Since the ball and rod is an isolated system and there is no external force on it so by momentum conservation we will have

here we also use angular momentum conservation
so we have

also we know that the collision is elastic collision so we have

so we have

also we know

also we know

so we have


now we have


Part b)
Now we know that speed of the ball after collision is given as

so it is given as
