Answer:
B. 14
Explanation:
For an element:
- Atomic number: is the number of protons in the nucleus (p)
- Mass number: it is the number of protons (p) + neutrons (n) in the nucleus
For Al (aluminium), we have:
p = 13
p + n = 27
Substituting the first equation into the second one, we find the number of neutrons:
n = 27 - p = 27 - 13 = 14
Answer:
a) Maximum height reached above ground = 2.8 m
b) When he reaches maximum height he is 2 m far from end of the ramp.
Explanation:
a) We have equation of motion v²=u²+2as
Considering vertical motion of skateboarder.
When he reaches maximum height,
u = 6.6sin58 = 5.6 m/s
a = -9.81 m/s²
v = 0 m/s
Substituting
0²=5.6² + 2 x -9.81 x s
s = 1.60 m
Height above ground = 1.2 + 1.6 = 2.8 m
b) We have equation of motion v= u+at
Considering vertical motion of skateboarder.
When he reaches maximum height,
u = 6.6sin58 = 5.6 m/s
a = -9.81 m/s²
v = 0 m/s
Substituting
0= 5.6 - 9.81 x t
t = 0.57s
Now considering horizontal motion of skateboarder.
We have equation of motion s =ut + 0.5 at²
u = 6.6cos58 = 3.50 m/s
a = 0 m/s²
t = 0.57
Substituting
s =3.5 x 0.57 + 0.5 x 0 x 0.57²
s = 2 m
When he reaches maximum height he is 2 m far from end of the ramp.
Answer:
12 A
Explanation:
Given,
Power of electric kettle=2.2 kW=2200W (since 1kW=1000W)
Voltage=180V
Current=?
Power = Voltage*Current
Current = Power ÷ Voltage
=2200W ÷ 180V
=12.22 Ampere
=12 A
The resultant force is 8N
Given that mass is 2kg , v= 40m/s, u =20m/s and we need to calculate resultant force
F=ma
m is given
so for a
v-u/t=a { first equation of motion }
40-20/4= 4
so a=4
F = ma =2*4 = 8N
The difference between the forces that are acting on an object as part of a system is known as the resultant force.
v = u + at is the first equation of motion. Here, v denotes the end speed, u the starting speed, an acceleration, and t the passage of time. The first equation of motion is provided by the velocity-time relation, which may be used to calculate acceleration.
To learn more about resultant force please visit -
brainly.com/question/22260425
#SPJ1
Step 1: Tell them to keep their eyes on the road.Step 2: Watch them to make sure they keep their eyes on the road.Step 3: Don't converse with them because you might risk distracting them.
It makes an awkward situation but it ensures that they'll feel so pressured to keep their eyes on the road or pull over so you can call a different ride.
