Given parameters:
Displacement = 8km
Velocity = 3.8km/h
Unknown:
time = ?
Solution:
Velocity is displacement divided by time.
Velocity =
Displacement = velocity x time
Input the parameters:
8 = 3.8 x time
Time = = 2.1s
The time taken is 2.1s
Answer:
Time taken by Jesse to bring his bicycle =5.4 Sec
Explanation:
acceleration of bicycle = -2.5 m/sec²
Initial velocity of by cycle u =13.5 m/sec,
final velocity of bicycle v = 0 (since bicycle completely stop finally)
Let the time taken to stop the bicycle completely = t sec
We now by equation of motion,
putting the value of u,v & a in the equation
0=13.5 -2.5 x t ( a is taken as negative since velocity of bicycle is reducing)
= 5.4 Sec
The mass of a radioactive element at time t is given by
where
is the mass at time zero, while
is the half-life of the element.
In our problem,
, t=121.0 s and
, so we can find the initial mass
:
Answer:
The magnitudes of the net magnetic fields at points A and B is 2.66 x T
Explanation:
Given information :
The current of each wires, I = 4.7 A
dH = 0.19 m
dV = 0.41 m
The magnetic of straight-current wire :
B= μI/2πr
where
B = magnetic field (T)
μ = 1.26 x (N/)
I = Current (A)
r = radius (m)
the magnetic field at points A and B is the same because both of wires have the same distance. Based on the right-hand rule, the net magnetic field of A and B is canceled each other (or substracted). Thus,
BH = μI/2πr
= (1.26 x )(4.7)/(2π)(0.19)
= 4.96 x T
BV = μI/2πr
= (1.26 x )(4.7)/(2π)(0.41)
= 2.3 x T
hence,
the net magnetic field = BH - BV
= 4.96 x - 2.3 x
= 2.66 x T