Answer:
I1 < I2
V1 > V2
Explanation:
Let the EMF of both the batteries is E and the internal resistance of both the cells is r.
The relation between the current and the EMF is given by
where, R be the resistance connected in the circuit.
the relation between the terminal potential difference and the EMF is given by
V = E - Ir
where, V is the terminal potential difference
If R1 is connected,
The current is given by
.... (1)
The terminal potential difference is given by
..... (2)
If R2 is connected,
The current is given by
.... (3)
The terminal potential difference is given by
..... (4)
As given in the question, R2 > R1
So, by the equation (1) and (3), we get
I1 < I2
and by the equation (2) and (4) ,we get
V1 > V2
Answer:
The speed of the ambulance is 4.66 m/s.
Explanation:
Given that,
The siren emitting a whine at 1570 Hz
The cyclist pedaling a bike at 2.45 m/s
The cyclist hears a frequency of 1560 Hz
We know that,
Speed of sound wave
We calculate the speed of the ambulance
Using Doppler effect,
Where,
= frequency of ambulance siren
= cyclist hears the frequency
=speed of source
= speed of observer
Put the value in to the formula
Hence, The speed of the ambulance is 4.66 m/s.
<h2>
The average force acting on the ball is 58 N upwards.</h2>
Explanation:
Force is given by rate of change of momentum.
Mass of ball = 0.60 kg
Initial velocity = -6.3 m/s downwards
Final velocity = 5.3 m/s upwards
Change in momentum = 0.6 x 5.3 - 0.6 x (-6.3)
Change in momentum = 6.96 kg m/s upwards
Time taken = 0.12 s
Rate of change of momentum = Change in momentum ÷ Time
Rate of change of momentum = 6.96 ÷ 0.12
Rate of change of momentum = 58 N upwards
Force = 58 N upwards
The average force acting on the ball is 58 N upwards.
Answer:
Static friction acts on stationary objects while kinetic friction acts on those in motion. Static friction is always greater or equal to kinetic friction. This can explain why objects often take more force to get in motion than it takes to continue their motion.