Answer:
B. 4700 J
Explanation:
Given the following data;
Mechanical energy = 4900J
Mass = 100kg
Velocity = 2m/s
To find the potential energy;
Mechanical energy = kinetic energy + potential energy
First of all, we would determine the kinetic energy of the object;
K.E = ½mv²
K.E = ½*100*2²
K.E = 50*4
K.E = 200 J
Substituting into the equation, we have;
4900 = 200 + P.E
P.E = 4900 - 200
P.E = 4700 Joules
Answer: a. F doubled
b. F reduced by one-quarter i.e
1/4*(F)
c. 1/9*(F)
d. F increased by a factor of 4 i.e 4*F
e. F reduces 3/4*(F)
Explanation: Coulombs law states the force F of attraction/repulsion experience by two charges qA and qB is directly proportional to thier product and inversely proportional to the square of distance d between them. That is
F = k*(qA*qB)/d²
a. If qA is doubled therefore the force is doubled since they are directly proportional.
b. If qA and qB are half, that means thier new product would be qA/2)*qB/2 =qA*qB/4
Which means the product of charge is divided by 4 so the force would be divided by 4 too since they are directly proportional.
c. If d is tripped that is multiplied by 3. From the formula new d would be (3*d)²=9d² but force is inversely proportional to d² so instead of multiplying by 9 the force will be divided by 9
d. If d is cut into half that is divided by 2. The new d would be (d/2)²=d²/4. So d² is divided by 4 so the force would be multiplied by 4
e. If qA is tripled that is multiplied by 3. F would be multiplied by 3 also, if at the same time d is doubled (2*d)²= 4*d² . Force would be divided by 4 at same time. So we have,
3/4*F
the answer should be "fluids".
The answer is 300kg times the 35 m/s10,500 kg•m/s
Answer: 2.3m/s
Explanation:
mass-energy balance: ke(f) + pe(f) = ke(o) + pe(o)
since we are looking for the point at the bottom of the pendulum, thats the reference point, the lowest in the system. pe(f) is 0, since h
ke(f)=0.5m x v(f)^2
pe(f)=0
ke(o)=0.5m x v(o)^2
pe(o)-mxgxh
find h by: drawing a triangle with the pendulum at the vertical, then displaced by 25 degrees , The difference in height is h, because cos(25)=(adj)/(hyp)=(2-h)/2. I found h=0.187m
In the m-e balance, cancel the masses in all the terms.
.5xv(f)^2 =0.5v(o)^2 +gxh
Given v(o) = 1.2 m/s and g = 9.8 then v(f) = 2.2595 m/s
Therefore V(0) = 2.3 m/s
