Answer:
r2/r1 = 1.3
Explanation:
Electric field is given as:
E = kq/r²
At a distance r1,
226 = kq/(r1)² - - - - - - - - - - - - - (1)
At a distance r2,
134 = kq/(r2)² - - - - - - - - - - - - - (2)
From (1),
kq = 226 * (r1)²
From (2),
kq = 134 * (r2)²
Equating and then solving,
134 * (r2)² = 226 * (r1)²
(r2)²/(r1)² = 226/134
(r2)²/(r1)² = 1.687
=> r2/r1 = 1.3
The lawnmower accelerates in the positive horizontal direction, so that the net horizontal force is, by Newton's second law,
(70 N) cos(-50°) = <em>m</em> (1.8 m/s²)
where <em>m</em> is the mass of the lawnmower. Solve for <em>m</em> :
<em>m</em> = ((70 N) cos(-50°)) / (1.8 m/s²)
<em>m</em> ≈ 25 kg
The lawnmower presumably doesn't get lifted off the ground, so that the net vertical force is 0. If <em>n</em> is the magnitude of the normal force, then by Newton's second law,
<em>n</em> - <em>m g</em> + (70 N) sin(-50°) = 0
<em>n</em> = <em>m g</em> + (70 N) sin(50°)
<em>n</em> = (25 kg) (9.8 m/s²) + (70 N) sin(50°)
<em>n</em> ≈ 300 N
Answer:
Conservation of energy
Explanation:
The first law of thermodynamics is given by :
Here,
Q is amount of heat added to the system
is change in internal energy
W is amount of work done by the system
It is clear that the energy can be neither created nor destroyed, it remains conserved. Hence, first law of thermodynamics shows that conservation of energy.
Compounds:
hydrogen
methane
hydrochloric acid
mixtures:
salt and water
oil and water
sugar and hot water
(stuff in day to day life basically)
Answer:
51.2 J, 86.2 J, 137.4 J
Explanation:
The kinetic energy of the ball is given by:
where
m = 0.40 kg is its mass
v = 16 m/s is its speed
Substituting,
The potential energy of the ball is given by
where
m = 0.40 kg
is the acceleration of gravity
h = 22 m is the heigth of the cliff
Substituting,
Finally, the total mechanical energy is the sum of the kinetic energy and the potential energy:
