As per the question the mass of the boy is 50 kg.
The boy sits on a chair.
We are asked to calculate the force exerted by the boy on the chair at sea level.
The force exerted by boy on the chair while sitting on it is nothing else except the force of gravity of earth i.e the weight of the body .The direction of that force is vertically downward.
At sea level the acceleration due to gravity g = 9.8 m/s^2
Hence the weight of the boy
[m is the mass of the body]
we have m = 50 kg.
Hence w = 50 kg ×9.8 m/s^2
=490 N kg m/s^2
= 490 N
Here newton [N] is the unit of force.
Hopes this helps:
Answer: Aluminum has 61 percent of the conductivity of copper, but has only 30 percent of the weight of copper. That means that a bare wire of aluminum weights half as much as a bare wire of copper that has the same electrical resistance. Aluminum is generally more inexpensive when compared to copper conductors.
Answer:
Watts=Volt*Amps
So A=570/120=4.75amps
If voltage drops to 110V We get A=570/110=5.(18...)amps
Answer:
a. 2.1 s
b.0.48 Hz
c. A=24cm
d. 72cm/s
Explanation:
An air-track glider attached to a spring oscillates between the 10.0 cm mark and the 57.0 cm mark on the track. The glider completes 15.0 oscillations in 31.0 s.What are the (a) period, (b) frequency, (c) amplitude, and (d) maximum speed of the glider?
What are the period,
period is the time taken for a wave particle to make one complete oscillation
a) 31 / 15 = 2.066 seconds
= 2.1 s
(b) frequency
: this the number of oscillation made in one seconds.
it is also the inverse of the period.
= oscillations / time
= 15/31= 0.48 Hz
(c) amplitude
: maximum displacement from the origin
amplitude = 1/2 of the difference of oscillation marks
= 1/2(57-10) = 47/2cm
23.5cm
A=24cm
(d) maximum speed of the glider?
V=ωA
angular frequency *Amplitude
V=a*pi*f*amplitude
2π x frequency x amplitude = maximum speed
= 2π x .48 x 24
=72.38 cm/s
72cm/s