A car of mass 500kg travelling at 36km/hr brought to rest over a distance of 20m calculate
1.The average retardation
2.The average braking force
Same procedure as your 6:17PM post.
Same procedure
I don't understand . Why the banning
To find the average retardation, we can use the equation:
v² = u² + 2as
Where:
- v is the final velocity (0 m/s in this case since the car comes to rest)
- u is the initial velocity, which is given as 36 km/hr (convert to m/s)
- a is the average retardation
- s is the distance traveled, which is given as 20 m
First, we need to convert the initial velocity from km/hr to m/s:
36 km/hr * (1000 m/1 km) * (1 hr/3600 s) = 10 m/s
Now we can substitute the values into the equation:
0² = (10 m/s)² + 2a(20 m)
0 = 100 + 40a
Solving for 'a', we have:
40a = -100
a = -100/40
a = -2.5 m/s²
The average retardation is -2.5 m/s² (negative sign indicates retardation).
To find the average braking force, we can use Newton's second law of motion:
F = ma
Where:
- F is the force
- m is the mass of the car, which is given as 500 kg
- a is the average retardation, which we found to be -2.5 m/s²
Substituting the values, we have:
F = (500 kg) * (-2.5 m/s²)
F = -1250 N
The average braking force is -1250 N (negative sign indicates that the force is acting in the opposite direction of motion).