Answer:
The speed of the car before it began to skid is 47.56 m/s.
Explanation:
We can use kinematics to solve this problem.
We are given three known variables:
- Δx = 290 m
- a = -3.90 m/s²
- v = 0 m/s (final velocity is 0 m/s because the car skids to a stop).
We can use this kinematic equation to <u><em>solve</em></u><em> for the initial velocity</em>, v₀.
Substitute the known variables into the equation.
- (0)² = v₀² + 2(-3.9)(290)
- 0 = v₀² - 2262
- 2262 = v₀²
- <u>v₀ = 47.56 m/s</u>
The speed of the car before it began to skid is 47.46 m/s.
They transfer energy. Not sure what your choices are but this is a common question
Answer:
A:- 50 J
B:- 500 J
Explanation:
a) Given that a 25 N force is applied to move the box. Also the floor is having friction surface.
So in order to move the box, the floor should have friction of atleast 25 N.
∴ friction = 25 N
Work done = force * displacement of box
Given, the box is moved 2 m across the floor
So, Work done = friction * 2 m
= 25 * 2
= 50 J
b) Given, the box is having weight of 250 N weight
Gravitational force is acting on the box which is equal to (mass * gravity)
∴ Force = 250 N
The box is lifted 2 m above the floor.
So, displacement = 2 m
Work done = force * displacement of box
Work done = 250 * 2
= 500 J
Answer:
Explanation:
An atom is constructed of three different particles known as electrons, protons and neutrons.
These particles have different mass and charges and are responsible for various characters than an atom posses.
An electron has a negative charge, a proton has positive charge and charge of neutron is neutral. Equal number of electrons and protons are present in an atom that make it electrically neutral but different conditions can occur if we remove these particles from an atom.
1 : Model of an ionized atom - an ionized atom is one which has some net charge on this. It can be either a positive charge or a negative charge.
If we need to sketch the model of an ionized atom then one should either keep the number of electrons less or proton.
2: Model of radioactive atom : A radioactive atom is one an unstable atom and has access of energy in its center. It can be caused by adding either neutrons or protons.
Answer:
Friction between two objects causes a transfer of electrons from one object to the other.
Explanation:
