A. One substance must dissolve in another
Answer:
Explanation:
Remark
In general, these 3rd class levers are very inefficient. Because the force distance is smaller than the load distance, you need to pull upward with more force that the weight of the load. So whatever the load is, the force is going to be much greater.
The distances are always measured to the pivot unless you are asked something specific otherwise.
Givens
F = ?
weight = 6N
Force Distance = F*d = 0.5 m
Weight Distance =W*d1 = 2 m
Formula
F*Fd = W*Wd
Solution
F*0.5 = 6 * 2 Divide by 0.5
F = 12/0.5
F = 24 N upwards
Answer:
v_2 = 2*v
Explanation:
Given:
- Mass of both charges = m
- Charge 1 = Q_1
- Speed of particle 1 = v
- Charge 2 = 4*Q_1
- Potential difference p.d = 10 V
Find:
What speed does particle #2 attain?
Solution:
- The force on a charged particle in an electric field is given by:
F = Q*V / r
Where, r is the distance from one end to another.
- The Net force acting on a charge accelerates it according to the Newton's second equation of motion:
F_net = m*a
- Equate the two expressions:
a = Q*V / m*r
- The speed of the particle in an electric field is given by third kinetic equation of motion.
v_f^2 - v_i^2 = 2*a*r
Where, v_f is the final velocity,
v_i is the initial velocity = 0
v_f^2 - 0 = 2*a*r
Substitute the expression for acceleration in equation of motion:
v_f^2 = 2*(Q*V / m*r)*r
v_f^2 = 2*Q*V / m
v_f = sqrt (2*Q*V / m)
- The velocity of first particle is v:
v = sqrt (20*Q / m)
- The velocity of second particle Q = 4Q
v_2 = sqrt (20*4*Q / m)
v_2 = 2*sqrt (20*Q / m)
v_2 = 2*v
Vt = Vboat - Vriver
Vt = 18 - 2.5 = 15.5 m/s
If the boat's direction is the same as the water, you sum the velocities of the river and the boat .
Answer:
because when squeezing you are increasing pressure within the bottle and there is less pressure on the outside
