Answer:
a) 0.1832 A
b) 11.91 Volts
c) 2.18 Watt , 0.0168 Watt
Explanation:
(a)
R = external resistor connected to the terminals of the battery = 65 Ω
E = Emf of the battery = 12.0 Volts
r = internal resistance of the battery = 0.5 Ω
i = current flowing in the circuit
Using ohm's law
E = i (R + r)
12 = i (65 + 0.5)
i = 0.1832 A
(b)
Terminal voltage is given as
= i R
= (0.1832) (65)
= 11.91 Volts
(c)
Power dissipated in the resister R is given as
= i²R
= (0.1832)²(65)
= 2.18 Watt
Power dissipated in the internal resistance is given as
= i²r
= (0.1832)²(0.5)
= 0.0168 Watt
Answer:
The angle of incident ray is 40°.
Explanation:
Given that the angle of incident and reflected ray are the same. In this question, we had given that both angles added up will gives you 80° so you have to divide it by 2 :
incident + reflected = 80°
Let incident = reflected = θ
θ + θ = 80°
2θ = 80°
θ = 80° ÷ 2
= 40°
Answer:
The speed of water must be expelled at 6.06 m/s
Explanation:
Neglecting any drag effects of the surrounding water we can assume the linear momentum in this case is conserves, that is, the total initial momentum of the octopus and the water kept in it cavity should be equal to the total final linear momentum. That's known as conservation of momentum, mathematically expressed as:
with Pi the total initial momentum and Pf the final total momentum. The total momentum is the sum of the momentums of the individual objects, in our case the octopus and the mass of water that will be expelled:
with Po the momentum of the octopus and Pw the momentum of expelled water. Linear momentum is defined as mass times velocity:
Note that initially the octopus has the water in its cavity and both are at rest before it sees the predator so 
:
We should find the final velocity of water if the final velocity of the octopus is 2.70 m/s, solving for 
:
The minus sign indicates the velocity of the water is opposite the velocity of the octopus.
Answer:
option (c)
Explanation:
When an object thrown upwards, the value of acceleration acting on the object is acceleration due to gravity which is always acting towards the earth.
As it falls downwards, the acceleration is again equal to the acceleration due to gravity.
So, the ball's acceleration is constant.
