Explanation:
<em><u>Principle of Floatation</u></em>
Principle of Floatation states that weight of floating body is equal to weight of water displaced by it
Answer:
91.5 m/s
Explanation:
m = mass of clay = 12 g = 0.012 kg
M = mass of wooden block = 100 g = 0.1 kg
d = distance traveled by the combination before coming to rest = 7.5 m
μ = Coefficient of friction = 0.65
V = speed of the combination of clay and lock just after collision
V' = final speed of the combination after coming to rest = 0 m/s
acceleration caused due to friction is given as
a = - μ g
a = - (0.65) (9.8)
a = - 6.37 m/s²
Using the kinematics equation
V'² = V² + 2 a d
0² = V² + 2(- 6.37) (7.5)
V = 9.8 m/s²
v = speed of clay just before collision
Using conservation of momentum
m v = (m + M) V
(0.012) v = (0.012 + 0.100) (9.8)
v = 91.5 m/s
Answer:
First answer.
Explanation:
There may be a 5N force, but if the frictional force also equals 5N, than they cancel eachother out, resulting in the brick still staying still, as it is resting on a (perfectly) level surface, but any amount of force would make the brick move.
Answer:
Explanation:
1 ) Total mechanical energy of the car at the height of 10 m
1/2 mv² + mgh
.5 x 1800 x 25² + 1800 x 9.8 x 10 m
= 562500 + 176400
738900 J
If v be the velocity at the bottom ,
Total energy of the car at the bottom
1/2 m v² + 0
Applying conservation of energy
1/2 mv² = 738900
.5 x 1800 v² = 738900
v = 28.65 m /s
Energy required by car to ascend height of 15 m
1800 x 9.8 x 15
= 264600 J
b )
This energy is more that total energy of the car at the top that is 738900 J
so car can easily reach gas station .
If V be the velocity at the gas point
Total energy at the gas point
1/2 m V² + 264600
Applying conservation of energy
1/2 m V² + 264600 =738900
.5 x 1800 x V² = 474300
V = 22.95 m / s
d ) If R be the normal reaction at the bottom
net force
R - mg = m v² / r
R = m ( g + v² / r )
1800 ( 9.8 + 28.65² / 5 )
R = 313136 N
Newton's second law is:
F=m*a,
where a=dv/dt, so
F=m*(dv/dt)
Rearranging gives:
F*dt=m*dv.
Basic integration gives:
F*t=m(vf-v0),
where vf and v0 are the final and initial velocities of the object respectively.
In your case vf=0, because the ball stops completely, and v0=10m/s.
Rearranging the last expression gives F=(m(vf-vo))/t.
Plug in numbers to find F=(2*10)/0.03=666.6 N
