Answer:
v = 108 m/s.
Explanation:
Given that,
The position of a particle moving on a straight line is given by :
We need to find the instantaneous velocity at t=5s.
Velocity,
So,
Instantaneous velocity at t = 5 s will be :
v = 18+18t
v = 18+18(5)
= 18 + 90
= 108 m/s
So, the instantaneous veloctiy at t=5s is 108 m/s.
Answer:
In summary, it is safe to handle this voltage with dry hands because the current value that you pass through the body is smaller than its underestimated sensitivity.
Explanation:
The current flowing through your system is described by Ohm's law
V = I R
where I is the current, V the voltage and R the resistance
in this case three barateras are taken in series giving a total voltage of V = 4.5 V the typical resistance values of dry skin is R = 1000 000Ohm and the resinification of wet skin is R = 100000 ohm
let's calculate the current flowing
I = V / R
I = 4.5 / 1000000
I = 4.5 10⁻⁶ A
this is the current with dry hands, we see that much less than the value that allows to feel a painful response by the body
If the skin is
I = 4,5 / 100,000
I = 4.5 10⁻⁵ A
This value is small, but it is close to the pain threshold, but it is in the range of slight discomfort.
In summary, it is safe to handle this voltage with dry hands because the current value that you pass through the body is smaller than its underestimated sensitivity.
Answer:
(a) 13.43 N
(b) 1.62 m/s2
Explanation:
(a)Let g = 9.81 m/s2
The pushing force can be split into 2 components: 1 parallel and the other perpendicular to the floor:
- The parallel component:
- The perpendicular component:
Friction force is the product of coefficient and normal force, which consists of gravity and the perpendicular pushing force
(b) Horizontally speaking, the net force acting on the block is the parallel force subtracted by friction
The block acceleration according to Newton's 2nd law is
Answer:
90.3125 m
Explanation:
a = 10m/s^2 (constant)
S=height
U=initial velocity
a= gravitational acceleration
t= time
s = 0 + 1/2 * 10 * 4.25 ^2
u is 0 because it is dropped without velocity
s =90.3125 m
Answer: Equal number of protons and electrons. Example: an atom of oxygen atom has 8 electrons and 8 protons and is neutral.
Explanation:
An atom that has no charge is a neutral atom. It contains electrons equal to protons. For example: A neutral atom of oxygen has 8 protons and 8 electrons.
An atom which has charge is said be ionized. It is either positively charged or negatively charged. It is positively charge when the number of electrons is less than the number of protons. For example: contains 10 electrons and 11 protons.
And when the number of electrons is greater than the number of protons, the atom is negatively charged. For example, has 17 protons and 18 electrons. It readily accepts an electron to complete its octet.