It will cause heat from friction
Answer:
The mass of the child + skateboard is 50 kg
Explanation:
In this problem, we can apply Newton's second law:
F = ma
where
F is the net force on a system
m is the mass of the system
a is the acceleration of the system
In this problem, our system is the child + the skateboard. The net force on them is
F = 75 N
and their acceleration is
So we can re-arrange the equation above to find their combined mass:
Answer:
The Gravitational force would decrease
Explanation:
To calculate FG the formula is:
Fg=mg
if mass decreases then the gravitational force would decrease
Answer:
<h2>
<u>Joule</u><u>:</u></h2>
1 Joule of work is said to be done when a force of 1 Newton is applied to move/displace a body by 1 metre.
1 Joule= 1 Newton × 1 metre
1 Newton is the amount of force required to accelerate body of mass 1 kg by 1m/s²
So units of N is kgm/s²
So,
1 Joule
=1kgm/s² × m
=1kgm²/s²
<h2><u>Erg</u><u>:</u></h2>
1 erg is the amount of work done by a force of 1 dyne exerted for a distance of one centimetre.
1 Erg =1 Dyne × 1 cm
1 dyne is the force required to cause a mass of 1 gram to accelerate at a rate of 1cm/s².
1 Erg=1 gmcm/s² × cm
1 Erg=1 gmcm/s² × cm=1gmcm²/s²
this is what you need to convert 1gmcm²/s² to 1kgm²/s²
<h3><u>
what you need to know for conversion</u></h3>
[1gm=0.001kg
1cm²
=1cm ×1cm
=0.01 m × 0.01 m
=0.0001m²
second remains constant
]
So,
1gmcm²/s²
=0.001kg×0.0001m²/s²
=0.001kg×0.0001m²/s² =0.0000001kgm²/s²
Hence,
<h3>
<u>1 Erg</u><u>=</u><u>0.0000001</u><u> </u><u>Joule</u></h3><h3>
<u>1</u><u> </u><u>Joule</u><u>=</u><u>1</u><u>0</u><u>,</u><u>0</u><u>0</u><u>0</u><u>,</u><u>0</u><u>0</u><u>0</u><u> </u><u>Erg</u></h3>
<h2>⇒15 J=15×10000000 Erg</h2><h2> =150000000 Erg</h2><h2>
=1.5×10⁶ Erg</h2>
Answer:
$v_f = = 7.9 \times10^3 \text{ m/s }$
