To develop this problem we will apply the concepts related to the kinematic equations of motion, specifically that of acceleration. Acceleration can be defined as the change of speed in an instant of time, mathematically this is
If a mobile is decreasing its speed (it is slowing down), then its acceleration is in the opposite direction to the movement. This would imply that the acceleration vector is opposite to the velocity vector.
Therefore the correct answer is B.
The time elapsed when the vehicles are closest to each other is 20 min.
The given parameters:
- Speed of the truck, u = 80 km/h
- Distance, d = 32 km
- Speed of the car, v = 50 km/h
<h3>Principles of relative speed</h3>
The time elapsed when the cars are close to each other is calculated by applying the principles of relative speed.
Thus, the time elapsed when the vehicles are closest to each other is 20 min.
Learn more about relative velocity here: brainly.com/question/24430414
Molecules Speed Up because the other three options only occur when the temperature is decreased.
Answer:
a) 39.6 m/s b) 4123 N
Explanation:
a) At the top of the loop, all of the forces point downwards (force of gravity and normal force).
Fnet=ma
ma=m(v^2/R) (centripetal acceleration)
mg=m(v^2/R)
m cancels out (this is why pilot feels weightless) so,
g=(v^2/R)
9.8 m/s^2 = v^2/160 m
v^2=1568 m^2/s^2
v=39.6 m/s
b) At the bottom of the loop, the normal force and the force of gravity point in opposite directions. The normal force is the weight felt.
Convert 300 km/hr to m/s
300 km/hr=83.3 m/s
Convert pilot's weight into mass:
760 N = 77.55 kg
Fnet=ma
n-mg=m(v^2/R)
n=(77.55 kg)(((83.3 m/s)^2)/160 m)+(77.55 kg)(9.8 m/s^2)
n=3363.2 N+760 N=4123 N
The force needed to give a car of mass 800 kg an acceleration of 2.0 ms-² is 1600N.
<h3>How to calculate force?</h3>
The force needed to push an object can be calculated by multiplying the mass of the object by its acceleration as follows:
Force = mass × acceleration
According to this question, a car of mass 800 kg has an acceleration of 2.0 ms−². The force is calculated as follows:
Force = 800kg × 2m/s²
Force = 1600N
Therefore, the force needed to give a car of mass 800 kg an acceleration of 2.0 ms-² is 1600N.
Learn more about force at: brainly.com/question/13191643
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