Answer:
Explanation:
We need the power equation here:
P = W/t where W is work and is defined as
W = F*displacement.
Force is a measure in Newtons, which is also weight. We have the mass of the piano, but we need to find the weight:
w = mg so
w = 166(9.8) so
w = 1600N, rounded to the correct number of sig dig. We use that now in the power equation:
and isolating the unknown:
so
t = 5.3 seconds
Answer:

Explanation:
GIVEN
diameter = 15 fm =
m
we use here energy conservation

there will be some initial kinetic energy but after collision kinetic energy will zero

on solving these equations we get kinetic energy initial
J ..............(i)
That is, the alpha particle must be fired with 35.33 MeV of kinetic energy. An alpha particle with charge q = 2 e
and gains kinetic energy K =e∆V ..........(ii)
by accelerating through a potential difference ∆V
Thus the alpha particle will
just reach the
nucleus after being accelerated through a potential difference ∆V
equating (i) and second equation we get
e∆V = 35.33 Me V

Answer:
Her angular speed (in rev/s) when her arms and one leg open outward is 
Explanation:
Initial moment of inertia when arms and legs in is 
Final moment of inertia when her arms and on leg open outward, 
Initial angular speed 
Let the final angular speed be 
Since external torque on her is zero so we can apply conservation of angular momentum

=>
=>
Thus her angular speed (in rev/s) when her arms and one leg open outward is 
Answer:
Acceleration is the derivative of velocity with time, but velocity is itself the derivative of position with time.
Explanation: