Assuming that the object starts at rest, we know the following values:
distance = 25m
acceleration = 9.81m/s^2 [down]
initial velocity = 0m/s
we want to find final velocity and we don't know the time it took, so we will use the kinematics equation without time in it:
Velocity final^2 = velocity initial^2 + 2 × acceleration × distance
Filling everythint in, we have:
Vf^2 = 0^2 + (2)(-9.81)(-25)
The reason why the values are negative is because they are going in the negative direction
Vf^2 = 490.5
Take the square root of that
Final velocity = 22.15m/s which is answer c
Answer:
Explanation:
The angular momentum of that same disk-sphere remains unchanged the very same way before and after the impact of the collision when the clay sphere adheres to the disk.
= constant.
The overall value of such moment of inertia is now altered when the clay spherical sticks. Due to the inclusion of the clay sphere, the moment of inertia will essentially rise. As a result of this increase, the angular speed w decreases in value.
Recall that:
The Kinetic energy is given by:
where;
is constant and w reduces;
As a result, just after the collision, the system's total kinetic energy decreases.
"6.5 km/hr" is not a velocity. It's just a speed, so
we don't know what direction he's walking.
If he happens to be walking north, then it takes him
(12 km) / (6.5 km/hr) = 1.846... hours (rounded) .
If he's walking in any other direction, it takes him longer than that.
If the angle between north and the direction he's walking is
90 degrees or more, then he can never cover any northward
distance, no matter how long he walks.
Explanation:
There's not enough information in the problem to solve it. We need to know either the initial speed of the lorry, or the time it takes to stop.
For example, if we assume the initial speed of the lorry is 25 m/s, then we can find the rate of deceleration:
v² = v₀² + 2aΔx
(0 m/s)² = (25 m/s)² + 2a (50 m)
a = -6.25 m/s²
We can then use Newton's second law to find the force:
F = ma
F = (7520 kg) (-6.25 m/s²)
F = -47000 N
