Answer:
15 cm
Step-by-step explanation:
Given that :
Reading at one end, initial reading = 3.5 cm
Reading at the other end, final reading = 18.5 cm
Length of needle :
Final Reading - Initial reading
18.5cm - 3.5cm
= 15cm
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.
So, the function is obviously shifted up by 1 so it rules out A and B, and we also see that the period is 4pi rather than 2pi, and using the fact that:
Now that we know our b value, we see that the correct answer would be C.
Answer is -23
Add 4 from both sides
Subtract 5 from both sides
Then divide 7
