As per the question the initial speed of the car [ u] is 42 m/s.
The car applied its brake and comes to rest after 5.5 second.
The final velocity [v] of the car will be zero.
From the equation of kinematics we know that
[ here a stands for acceleration]
Here a is taken negative as it the car is decelerating uniformly.
We are asked to calculate the stopping distance .
From equation of kinematics we know that
[here S is the distance]
![= 42*5.5 +\frac{1}{2} [-7.64] [5.5]^2 m](https://tex.z-dn.net/?f=%3D%2042%2A5.5%20%2B%5Cfrac%7B1%7D%7B2%7D%20%5B-7.64%5D%20%5B5.5%5D%5E2%20m)
[ans]
Answer:
1. Motion
2. Empty space
3. Far apart
4. Independently
5. Random or rapid
6. Collision
7. Kinetic energy
8. Atmospheric
9. 273 Kelvin or 0° Celsius
10. 1 atm, 101.3 kPa or 760 mmHg
Explanation:
In science, matter can be defined as anything that has mass and occupies space. Any physical object that is found on earth is typically composed of matter. Matter are known to be made up of atoms and as a result has the property of existing in states.
Generally, matter exists in three (3) distinct or classical phases and these are;
I. Gas.
II. Solid.
III. Liquid.
Filling the missing words or texts in the question, we have;
The kinetic theory describes the motion of particles in matter and the forces of attraction between them. The theory assumes that the volume occupied by a gas is mostly empty space, that the particles of gas are relatively far apart, move independently of each other, and are in constant random or rapid motion. The collision between particles are perfectly elastic so that the total kinetic energy remains constant. Gas pressure results from the simultaneous collisions of billions of particles with an object. Barometers are used to measure atmospheric pressure. Standard conditions are defined as a temperature of 273 Kelvin or 0° Celsius and a pressure of 1 atm, 101.3 kPa or 760 mmHg.
Answer:
The speed of the block is 8.2 m/s
Explanation:
Given;
mass of block, m = 2.1 kg
height above the top of the spring, h = 5.5 m
First, we determine the spring constant based on the principle of conservation of potential energy
¹/₂Kx² = mg(h +x)
¹/₂K(0.25)² = 2.1 x 9.8(5.5 +0.25)
0.03125K = 118.335
K = 118.335 / 0.03125
K = 3786.72 N/m
Total energy stored in the block at rest is only potential energy given as:
E = U = mgh
U = 2.1 x 9.8 x 5.5 = 113.19 J
Work done in compressing the spring to 15.0 cm:
W = ¹/₂Kx² = ¹/₂ (3786.72)(0.15)² = 42.6 J
This is equal to elastic potential energy stored in the spring,
Then, kinetic energy of the spring is given as:
K.E = E - W
K.E = 113.19 J - 42.6 J
K.E = 70.59 J
To determine the speed of the block due to this energy:
KE = ¹/₂mv²
70.59 = ¹/₂ x 2.1 x v²
70.59 = 1.05v²
v² = 70.59 / 1.05
v² = 67.229
v = √67.229
v = 8.2 m/s
