The correct statements are:
B. a small rock sitting on top of a big rock
As the rock is at a height with respect to ground it has potential Energy
and
C. a stretched rubber band
A stretched rubber band has elastic potential energy
The others are actually moving and hence would consist of Kinetic energy. Potential energy is stored in objects that do not move and are stationary.
Answer:
Explanation:
Block A sits on block B and force is applied on block A . Block A will experience two forces 1) force P and 2 ) friction force in opposite direction of motion . Block B will experience one force that is force of friction in the direction of motion .
Let force on block A be P . friction force on it will be equal to kinetic friction, that is μ mg , where μ is coefficient of friction and m is mass of block A
friction force = .4 x 2.5 x 9.8
= 9.8 N
net force on block A = P - 9.8
acceleration = ( P - 9.8 ) / 2.5
force on block B = 9.8
acceleration = force / mass
= 9.8 / 6
for common acceleration
( P - 9.8 ) / 2.5 = 9.8 / 6
( P - 9.8 ) / 2.5 = 1.63333
P = 13.88 N .
The average force applied to the ball= 106.7 N
Explanation:
Force is given by
f= ΔP/t
ΔP= change in momentum= m Vf- m Vi
m= mass =0.2 kg
Vf= final velocity= 12 m/s
Vi=initial velocity= -20 m/s ( negative because it is going towards the wall which is treated as negative axis)
t= time= 60 ms= 0.06 s
now ΔP= 0.2 [ 12-(-20)]
ΔP=0.2 (32)=6.4 kg m/s
now force F= ΔP/t
F= 6.4/0.06
F=106.7 N
Nuclear Fission s a power source with a very low environmental impact.
Answer:106560 N
Explanation:
Given
Let Tension between 2 and 3 car be 
and between 3 &4 is 
mass of freight car =37,000 kg
acceleration of car
is accelerating all freights behind 3
therefore
Thus
