Answer:
1977.696 J
Explanation:
Given;
Weight of the box = 28.0 kg
Force applied by the boy = 230 N
angle between the horizontal and the force = 35°
Therefore,
the horizontal component of the force = 230 × cosθ
= 230 × cos 35°
= 188.405 N
Coefficient of kinetic friction, μ = 0.24
Force by friction, f = μN
here,
N = Normal force = Mass × acceleration due to gravity
or
N = 28 × 9.81 = 274.68 N
therefore,
f = 0.24 × 274.68
or
f = 65.9232 N
Now,
work done by the boy, W₁ = 188.405 N × Displacement
= 188.405 N × 30
= 5652.15 J
and,
the
work done by the friction, W₂ = - 65.9232 N × Displacement
= - 65.9232 N × 30 m
= - 1977.696 J
[ since the friction force acts opposite to the direction of motion, therefore the workdone will be negative]
Answer:
Explanation:
v = Velocidad final =
u = Velocidad inicial = 0
t = Tiempo empleado = 15 s
a = Aceleración
De las ecuaciones cinemáticas tenemos
La aceleración del camión en el primer intervalo de tiempo es .
No
It means the resultant electrical charges had canceled each other out so there is no field to be sensed .
Answer:
This is because the 11 positive protons and 10 negative electrons end up with an overall charge of +1.
Explanation:
Answer:
L = 4.58 x 10⁴ kg.m²/s
Explanation:
The angular momentum is given by the formula:
L = mvr
but, v = rω
Therefore,
L = mr²ω
where,
L = Angular Momentum of the person = ?
m = mass of person = 99 kg
r = radius of earth = 6.37 x 10⁶ m
ω = Angular Speed of Earth's Rotation = θ/t
Since, earth completes 1 rotation in 1 day. Hence,
ω = (2π rad/1 day)(1 day/24 h)(1 h/3600 s)
ω = 7.27 x 10⁻⁵ rad/s
Therefore,
L = (99 kg)(6.37 x 10⁶ m)²(7.27 x 10⁻⁵ rad/s)
<u>L = 4.58 x 10⁴ kg.m²/s</u>