The awnser to this problem is either 12 or 7 by using multiplication or addition
<span>it all looks confusing when we try to juggle with all those numbers in the head. The problem can be solved systematically by constructing a contingency table.
</span>role/gender B G total
speaking...... 4 4 8
<span> silent............ 4 8 12
total............. 8 12 20
</span>Probability of a child having a speaking part is therefore
(4+4)/20=8/20=2/5
a. 2/5
Answer:
Rolling case achieves greater height than sliding case
Step-by-step explanation:
For sliding ball:
- When balls slides up the ramp the kinetic energy is converted to gravitational potential energy.
- We have frictionless ramp, hence no loss due to friction.So the entire kinetic energy is converted into potential energy.
- The ball slides it only has translational kinetic energy as follows:
ΔK.E = ΔP.E
0.5*m*v^2 = m*g*h
h = 0.5v^2 / g
For rolling ball:
- Its the same as the previous case but only difference is that there are two forms of kinetic energy translational and rotational. Thus the energy balance is:
ΔK.E = ΔP.E
0.5*m*v^2 + 0.5*I*w^2 = m*g*h
- Where I: moment of inertia of spherical ball = 2/5 *m*r^2
w: Angular speed = v / r
0.5*m*v^2 + 0.2*m*v^2 = m*g*h
0.7v^2 = g*h
h = 0.7v^2 / g
- From both results we see that 0.7v^2/g for rolling case is greater than 0.5v^2/g sliding case.
Answer:
30%
Step-by-step explanation:
A 25% discount means u paid 75%
75% of the original price is 18...
0.75x = 18.....with x being the original price
x = 18 / 0.75
x = 24 <== the original price
