Answer:
Explanation:
Force of friction at car B ( break was applied by car B ) =μ mg = .65 x 2100 X 9.8 = 13377 N .
work done by friction = 13377 x 7.30 = 97652.1 J
If v be the common velocity of both the cars after collision
kinetic energy of both the cars = 1/2 ( 2100 + 1500 ) x v²
= 1800 v²
so , applying work - energy theory ,
1800 v² = 97652.1
v² = 54.25
v = 7.365 m /s
This is the common velocity of both the cars .
To know the speed of car A , we shall apply law of conservation of momentum .Let the speed of car A before collision be v₁ .
So , momentum before collision = momentum after collision of both the cars
1500 x v₁ = ( 1500 + 2100 ) x 7.365
v₁ = 17.676 m /s
= 63.63 mph .
( b )
yes Car A was crossing speed limit by a difference of
63.63 - 35 = 28.63 mph.
Answer:
Explanation:
As we know that the radius of the circular motion is given as
time period of the motion is given as
now we know that it is moving with uniform speed
so it is given as
now plug in all data
A. Increase Energy because simple machines are supposed to help humans use less energy and less force when doing a task that normally requires a lot of force and energy
Answer:
153.6 kN
Explanation:
The elastic constant k of the block is
k = E * A/l
k = 95*10^9 * 0.048*0.04/0.25 = 729.6 MN/m
0.12% of the original length is:
0.0012 * 0.25 m = 0.0003 m
Hooke's law:
F = x * k
Where x is the change in length
F = 0.0003 * 729.6*10^6 = 218.88 kN (maximum force admissible by deformation)
The compressive load will generate a stress of
σ = F / A
F = σ * A
F = 80*10^6 * 0.048 * 0.04 = 153.6 kN
The smallest admisible load is 153.6 kN
Answer: 7291.2 joules
Explanation:
Work is done when force is applied on an object over a distance.
Thus, Workdone = Force X distance
Since Distance moved by box = 12 metres
mass of box = 62kg
Acceleration due to gravity when box was lifted is represented by g = 9.8m/s^2
Recall that Force = Mass x acceleration due to gravity
i.e Force = 62kg x 9.8m/s^2
= 607.6 Newton
So, Workdone = Force X Distance
Workdone = 607.6 Newton X 12 metres
Workdone = 7291.2 joules
Thus, 7291.2 joules of work was done.
