Answer:
Step-by-step explanation:
As given
if n erasers have a weight of 80 grams .
I.e
n erasera = 80 grams.
1 erasers weight .
Now find out the weight of the 50 erasers.
Simplify the above
Answer:
x= 90-60
x=30
Step-by-step explanation:
Answer:
7 miles
Step-by-step explanation:
Mr. Luna's travels east and west are irrelevant to the question. He drives 3 miles north, then he drives 4 more miles north. 3 + 4 = 7, so Mr. Luna ends up 7 miles north of his home.
Answer:
$1,800
Step-by-step explanation:
If Michael works 30 hours a week for $15 an hour we can use the equation:
15 x 30 = 450.
Now just multiply the given answer by 4 and you're left with:
450 x 4 = 1800.
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.
