Answer:
i. 6.923 V
ii. The e.m.f. = 22.5 V
Explanation:
i. The given parameters are;
Length of potentiometer = 1 m
The resistance of the potentiometer = 10 Ω
The e. m. f. of the attached cell = 9 V
The current, I flowing in the circuit = e. m. f/(Total resistance)
The current, I flowing in the circuit = 9 V/(10 + 3) = 9/13 A
The potential difference, p.d. across the 1 m potentiometer wire = I × Resistance of the potentiometer wire
The p.d. across the potentiometer wire = 9/13×10 = 90/13 = 6.923 V
ii) Given that the 1 m potentiometer wire has a resistance of 10 Ω, 75 cm which is 0.75 m will have an e.m.f. given by the following relation;
Where:
E = e.m.f. of the balance point cell
= Resistance of 75 cm of potentiometer wire = 0.75×10 = 7.5 Ω
= Resistance of the cell in the circuit = 3 Ω
V = e.m.f. attached cell = 9 V
E = 7.5*3 = 22.5 V
The e.m.f. = 22.5 V
First, we need the distance of Europe and Wolf-359 from Earth.
- The distance of Europe from Earth is:
- The distance of Wolf-359 from Earth is instead 7.795 light years. However, we need to convert this number into km. 1 light year is the distance covered by the light in 1 year. Keeping in mind that the speed of light is
, and that in 1 year there are
365 days x 24 hours x 60 minutes x 60 seconds =
, the distance between Wolf-359 and Earth is
Now we can calculate the time the spaceship needs to go to Wolf-359, by writing a simple proportion. In fact, we know that the spaceship takes 2 years to cover
, so
from which we find
, the time needed to reach Wolf-359:
Answer:
The correct answer is;
The magnitude of the force is 35.12 N
Explanation:
To solve the question, we note that the friction is zero and the force causes motion of a stationary mass
One of the equations of motion is required such as
v² = u² + 2× a× s
Where
v = Final velocity = 5.93 m/s
u = Initial velocity = 0 m/s , object at rest
a = acceleration
s = distance moved = 32 meters
But v = Distance/Time = 32 m /5.4 s = 5.93 m/s
Therefore
5.93² = 2×a×32
or a = 35.12/ 64 = 0.55 m/s²
Therefore Force F = Mass m × Acceleration a
Where mass m = 64 kg
Therefore F = 64 kg×0.55 m/s² = 35.12 N
Answer:
the minimum time interval is 0.77 seconds
Explanation:
given data
coefficient of static friction = 0.5
coefficient of static friction shoes= 0.825
travel s = 2.40 m
to find out
what is the minimum time interval
solution
we know newton 2nd law
force = mass × acceleration
and
force acting on person due to friction
force = coefficient of static friction shoes × mg
so we can say
coefficient of static friction shoes × mg = ma
so
a = coefficient of static friction shoes × g
and we know g is 9.8 m/s²
so
distance formula by kinematic relation
distance = ut + 0.5 × at²
here put a value and u is zero because initial speed
2.40 = 0 + 0.5 × coefficient of static friction shoes × g× t²
2.40 = 0.5 × 0.825 × 9.8 × t²
t = 0.77 s
the minimum time interval is 0.77 seconds
