if brakes were applied to a already moving car with a speed of 72 kilometre per hour to reduce it to the speed of 18 kilometre per hour in 10 seconds calculate ​

Acceleration, a = -0.5 m/s²

Explanation:

Given the following data;

Initial velocity = 72 km/h

Final velocity = 18 km/h

Time = 10 seconds

To find the acceleration of the car;

Conversion:

72 km/h to m/s = 72*1000/3600 = 20m/s

18 km/h to m/s = 18*1000/3600 = 5 m/s

In physics, acceleration can be defined as the rate of change of the velocity of an object with respect to time.

This simply means that, acceleration is given by the subtraction of initial velocity from the final velocity all over time.

Hence, if we subtract the initial velocity from the final velocity and divide that by the time, we can calculate an object’s acceleration.

Mathematically, acceleration is given by the equation;

Substituting into the equation;

Acceleration, a = -0.5 m/s²

Therefore, the car is decelerating.

if the person is shown to have +90n, then ans is -10n.

if the person is shown to have -90n, then ans is +10n.

electromagnetic shielding is the practice of reducing the electromagnetic field in a space by blocking the field with barriers made of conductive or magnetic materials. shielding is typically applied to enclosures to isolate electrical devices from their surroundings, and to cables to isolate wires from the environment through which the cable runs. electromagnetic shielding that blocks radio frequency electromagnetic radiation is also known as rf shielding.

the shielding can reduce the coupling of radio waves, electromagnetic fields and electrostatic fields. a conductive enclosure used to block electrostatic fields is also known as a faraday cage. the amount of reduction depends very much upon the material used, its thickness, the size of the shielded volume and the frequency of the fields of interest and the size, shape and orientation of apertures in a shield to an incident electromagnetic

from wikipedia