Complete question:
Seat belts and air bags save lives by reducing the forces exerted on the driver and passengers in an automobile collision. Cars are designed with a "crumple zone" in the front of the car. In the event of an impact, the passenger compartment decelerates over a distance of about 1 m as the front of the car crumples. An occupant restrained by seat belts and air bags decelerates with the car. In contrast, a passenger not wearing a seat belt or using an air bag decelerates over a distance of 5mm.
(a) A 60 kg person is in a head-on collision. The car's speed at impact is 15 m/s . Estimate the net force on the person if he or she is wearing a seat belt and if the air bag deploys.
Answer:
The net force on the person as the air bad deploys is -6750 N backwards
Explanation:
Given;
mass of the passenger, m = 60 kg
velocity of the car at impact, u = 15 m/s
final velocity of the car after impact, v = 0
distance moved as the front of the car crumples, s = 1 m
First, calculate the acceleration of the car at impact;
v² = u² + 2as
0² = 15² + (2 x 1)a
0 = 225 + 2a
2a = -225
a = -225 / 2
a = -112.5 m/s²
The net force on the person;
F = ma
F = 60 (-112.5)
F = -6750 N backwards
Therefore, the net force on the person as the air bad deploys is -6750 N backwards
Different: The weak nuclear force is responsible for radioactive decay within an atom of a substance, while the electromagnetic force causes electrostatic force between charged particles.
Different: The weak force has a very small range of effectiveness (where the force can be felt) while the electromagnetic force has an infinite range.
Same: Both forces act within an nucleus, or on a nuclear level.
Same: The weak nuclear force is mediated by charged particles called bosons, and the electrostatic force is only present within charged objects
The last one may be a bit of a stretch but I hope this helped a bit!
Answer: D. The force and displacement are in the same direction.
Explanation:
The Work 
done by a Force 
refers to the release of potential energy from a body that is moved by the application of that force to overcome a resistance along a path with distance 
.
Work is a scalar magnitude, and its unit in the International System of Units is the Joule (like energy).
Now, when the applied force is constant and the direction of the force and the direction of the displacement are <u>parallel</u>, the equation to calculate it is:
(1)
When they are not parallel, both directions form an angle, let's call it 
. In that case the expression to calculate the Work is:
(2)
When the force and displacement are perpendicular to each other,
and <u>no work is done</u>.
Yes, the magnetic field of a wire carrying a current forms a cylinder shape around the wire, but that's not similar to the field of a bar magnet.
Answer:
a = 2.5 m/s^2
Explanation:
u = 0
v = 25
t = 10
(using first eq. of motion)
a = (v - u) /t
a = (25 - 0) /10
a = 25/10
a = 2.5 m/s^2
