Answer:
B. The presence of an unbalanced force(e.g friction) causes a moving object to stop.
Explanation:
As the friction is that force that can stop the sled upon reaching the levelled surface so the option b is correct.
Answer:
–735.17 N
The negative sign indicate that the force is acting in opposition direction to the car.
Explanation:
The following data were obtained from the question:
Mass (m) of car = 782.10 kg
Initial velocity (u) = 7.60 m/s
Final velocity (v) = 3.61 m/s
Time (t) = 4.23 s
Force (F) =?
Next, we shall determine the acceleration of the car. This can be obtained as follow:
Initial velocity (u) = 7.60 m/s
Final velocity (v) = 3.61 m/s
Time (t) = 4.23 s
Acceleration (a) =?
a = (v – u) / t
a = (3.61 – 7.60) / 4.23
a = –3.99 / 4.23
a = –0.94 m/s²
Finally, we shall determine the force experienced by the car as shown below:
Mass (m) of car = 782.10 kg
Acceleration (a) = –0.94 m/s²
Force (F) =?
F = ma
F = 782.10 × –0.94
F = –735.17 N
The negative sign indicate that the force is acting in opposition direction to the car.
Distance=2m
because 200cm = 2m
so 4m-2m=2m
Answer:
magnitude of the frictional torque is 0.11 Nm
Explanation:
Moment of inertia I = 0.33 kg⋅m2
Initial angular velocity w° = 0.69 rev/s = 2 x 3.142 x 0.69 = 4.34 rad/s
Final angular velocity w = 0 (since it stops)
Time t = 13 secs
Using w = w° + §t
Where § is angular acceleration
O = 4.34 + 13§
§ = -4.34/13 = -0.33 rad/s2
The negative sign implies it's a negative acceleration.
Frictional torque that brought it to rest must be equal to the original torque.
Torqu = I x §
T = 0.33 x 0.33 = 0.11 Nm
higher temp = higher energy = higher frequency = shorter wavelength
