Answer:
The sled needed a distance of 92.22 m and a time of 1.40 s to stop.
Explanation:
The relationship between velocities and time is described by this equation:
, where
is the final velocity,
is the initial velocity,
the acceleration, and
is the time during such acceleration is applied.
Solving the equation for the time, and applying to the case:
, where
because the sled is totally stopped,
is the velocity of the sled before braking and,
is negative because the deceleration applied by the brakes.
In the other hand, the equation that describes the distance in term of velocities and acceleration:
, where
is the distance traveled,
is the initial velocity,
the time of the process and,
is the acceleration of the process.
Then for this case the relationship becomes:
.
<u>Note that the acceleration is negative because is a braking process.</u>
Answer:
Explanation:
The net force on the potatoes is given by:
F= 52 - mgSintheta
F= 52- (2×9.8× Sin70°)
F = 52 -18.4
F= 33.58N
Using Newton's 2nd law
F = ma
a=F/m = 33.58/ 2 = 16.79m/s^2
Using the equation of motion:
V^2= u^2 + 2as
V^2 = 0 + 2× 16.79 x2
V^2 = 67.16
V=sqrt(68.16)
V= 8.195m/s This is the exit velocity of the potatoes
Kinetic energy, K.E = 1/2mv^2
KE= 1/2 × 2 × 8.195^2
KE = 67.16J
Answer:
B) Diphosphorus pentoxide
Explanation:
It is itself. This question does not make sense.
Answer:
t_total = 23.757 s
Explanation:
This is a kinematics exercise.
Let's start by calculating the distance and has to reach the limit speed of
v = 18.8 m / s
v = v₀ + a t₁
the elevator starts with zero speed
v = a t₁
t₁ = v / a
t₁ = 18.8 / 2.40
t₁ = 7.833 s
in this time he runs
y₁ = v₀ t₁ + ½ a t₁²
y₁ = ½ a t₁²
y₁ = ½ 2.40 7.833²
y₁ = 73.627 m
This is the time and distance traveled until reaching the maximum speed, which will be constant throughout the rest of the trip.
x_total = x₁ + x₂
x₂ = x_total - x₁
x₂ = 373 - 73,627
x₂ = 299.373 m
this distance travels at constant speed,
v = x₂ / t₂
t₂ = x₂ / v
t₂ = 299.373 / 18.8
t₂ = 15.92 s
therefore the total travel time is
t_total = t₁ + t₂
t_total = 7.833 + 15.92
t_total = 23.757 s