If an object is moving, then its speed and the magnitude
of its velocity aren't zero.
If its velocity is constant (speed doesn't change and it's
moving in a straight line), then its acceleration is zero.
Looks like choice-D sums it up nicely.
A 300-kg bear grasping a vertical tree slides down at constant velocity. The friction force between the
tree and the bear is
Answer: according to https://www.doe.virginia.gov When light strikes translucent materials, only some of the light passes through them. The light does not pass directly through the materials. ... Opaque objects block light from traveling through them. Most of the light is either reflected by the object or absorbed and converted to thermal energy.
Explanation:
This is a problem that would be a good test of your understanding rather than your ability to work the formulas. 5m/s² means that the velocity increase each second is 5 m/s. So 4 s of that acceleration would increase the speed (in m/s) from 20 to 40. (Speed increase each second is 5 m/s. We need an increase of 20 m/s.)
Since the acceleration is uniform during those 4 s, we can use the simple average speed of 30 m/s. 30 m/s * 4 s = 120 m.
Answer:
The time taken for the train to cross the bridge is 9.01 s
Explanation:
Given;
length of the train, L₁ = 90 m
length of the bridge, L₂ = 0.06 m
speed of the train, v = 10 m/s
Total distance to be traveled, = L₁ + L₂
= 90 m + 0.06 m
= 90.06 m
Time of motion = Distance / speed
Time of motion = 90.06 / 10
Time of motion = 9.006 s ≅ 9.01 s
Therefore, the time taken for the train to cross the bridge is 9.01 s
