Answer:
W = 7000 J
Explanation:
To solve this problem we use that the speed of the bicycle is constant, therefore its acceleration is zero
F -fr = 0
F = fr
where F is the force applied by the child
Work is defined by
W = F. x
W = F x cos θ
in this case the child's force is parallel to the movement, therefore the angle is zero and cos 0 = 1
let's calculate
W = 35 200
W = 7000 J
Answer:
u = 25 m/s
Explanation:
given,
length of skid = 93 m
coefficient of friction = 0.35
final velocity = 0 m/s
initial velocity = ?
force here is friction f = μ mg
F = ma
now com paring
-μ mg = m a
a = - μ g
a = - 0.35 x 9.8
a = -3.43 m/s²
we know,
v² = u² + 2 a s
0 = u² - 2 x 3.43 x 93
u² = 637.98
u = 25.26 m/s
u = 25 m/s (two significant figure)
Answer:
28.23 years
Explanation:
I = 1100 A
L = 230 km = 230, 000 m
diameter = 2 cm
radius, r = 1 cm = 0.01 m
Area, A = 3.14 x 0.01 x 0.01 = 3.14 x 10^-4 m^2
n = 8.5 x 10^28 per cubic metre
Use the relation
I = n e A vd
vd = I / n e A
vd = 1100 / (8.5 x 10^28 x 1.6 x 10^-19 x 3.14 x 10^-4)
vd = 2.58 x 10^-4 m/s
Let time taken is t.
Distance = velocity x time
t = distance / velocity = L / vd
t = 230000 / (2.58 x 10^-4) = 8.91 x 10^8 second
t = 28.23 years
Hello =D
This problem is about cinematic
So
V = 45 mi/h
t = 2 h
Then
V= X/t
X = V*t
Then
X = (45)*(2)
X = 90 mi
Best regards
Answer:
The acceleration required by the rocket in order to have a zero speed on touchdown is 19.96m/s²
The rocket's motion for analysis sake is divided into two phases.
Phase 1: the free fall motion of the rocket from the height 2.59*102m to a height 86.9m
Phase 2: the motion of the rocket due to the acceleration of the rocket also from the height 86.9m to the point of touchdown y = 0m.
Explanation:
The initial velocity of the rocket is 0m/s when it started falling from rest under free fall. g = 9.8m/s² t1 is the time taken for phase 1 and t2 is the time taken for phase2.
The final velocity under free fall becomes the initial velocity for the accelerated motion of the rocket in phase 2 and the final velocity or speed in phase 2 is equal to zero.
The detailed step by step solution to the problems can be found in the attachment below.
Thank you and I hope this solution is helpful to you. Good luck.
