Answer:
(a) 20 m
(b) 6 m/s²
(c) Between t=0 and t=2, the body moves to the left.
Between t=2 and t=4, the body moves to the right.
Explanation:
v = 3t² − 6t
x(0) = 4
(a) Position is the integral of velocity.
x = ∫ v dt
x = ∫ (3t² − 6t) dt
x = t³ − 3t² + C
Use initial condition to find value of C.
4 = 0³ − 3(0)² + C
4 = C
x = t³ − 3t² + 4
Find position at t = 4.
x = 4³ − 3(4)² + 4
x = 20
(b) Acceleration is the derivative of velocity.
a = dv/dt
a = 6t − 6
Find acceleration at t = 2.
a = 6(2) − 6
a = 6
(c) v = 3t² − 6t
v = 3t (t − 2)
The velocity is 0 at t = 0 and t = 2. Evaluate the intervals.
When 0 < t < 2, v < 0.
When t > 2, v > 0.
The problem wants to compute how long does it take for the acceleration to occur if a car travelling at 7m/s accelerates uniformally at 2.5 m/s^2 to reach a speed of 12 m/s and base on that, the time duration would be 2 seconds. I hope this would help
Answer:
Explanation:
The potential difference between one side of the wire causes the electric field inside the wire (causes the electrons to flow). However, inside the wire, it is still neutral. The electrons are just moving, the wire is not gaining or losing electrons.
Answer:
white star
Explanation:
because it is the hottest form of a star
Answer:
Explanation:
First of all we shall calculate the velocity of composite mass . Let it be v . Applying law of conservation of momentum
mu - MU = ( m + M ) v
v = mu - MU / ( m + M )
loss of kinetic energy
= 1/ 2 mu² + 1/2 MU² - 1/2 ( M +m ) v²
= 1/ 2 mu² + 1/2 MU² - 1/2 ( M +m ) (mu - MU)² / ( m + M )²
= 1/ 2 mu² + 1/2 MU² - 1/2 (mu - MU)² / ( m + M )
= 1/2 [ m²u² + mMu² +mMU² + m²U² - m²u² - M²U² - 2 muMU ] / ( m + M )
= 1 / 2 [ mMu² + mMU² - 2 muMU ] / ( m + M )
= 1 / 2mM [ (u² + U² - 2 uU) / ( m + M )]
= 1/2 mM x k
where
k = [ (u² + U² - 2 uU) / ( m + M )]
Given
m = .004 kg
M = 4 kg
u = 890 ms⁻¹
U = 7 ms⁻¹
k = ( 890² + 7² - 2 x 890 x 7 ) / 4.004
= ( 792100 + 49 - 12460 ) / 4.004
= 194727.52
loss of kinetic energy
= 1/2 mM x k
= .5 x .004 x 4 x 194727.52
= 1557.82 J .
