Answer:
400m
Explanation:
use formula
velocity = displacement /time
According to the plot, the positions at time <em>t</em> = 0 s and <em>t</em> = 19 s are -1 m and -2 m, respectively. So the average velocity for the 19-s interval is

Answer:
<h3>The answer is option B</h3>
Explanation:
The frequency of a wave can be found by using the formula

where
c is the velocity
From the question
wavelength = 0.39 m
c = 86 m/s
We have

We have the final answer as
<h3>200 Hz</h3>
Hope this helps you
Answer:
P = 25299.75 watts
Since 80km/h is the average speed of 92km/h and 68km/h, the power (in watts) is needed to keep the car traveling at a constant 80 km/h is P = 25299.75 watts
Explanation:
Given;
Mass of car m = 1280kg
initial speed v1 = 92km/h = 92×1000/3600 m/s= 25.56m/s
Final speed v2 = 68km/h = 68×1000/3600 m/s= 18.89m/s
time taken t = 7.5s
Change in the kinetic energy of the car within that period;
∆K.E = 1/2 ×mv1^2 - 1/2 × mv2^2
∆K.E = 0.5m(v1^2 -v2^2)
Substituting the values, we have;
∆K.E = 0.5×1280(25.56^2 - 18.89^2)
∆K.E = 189748.16J
Power used during this Change;
Power P = ∆K.E/t
Substituting the values;
P = 189748.16/7.5
P = 25299.75 watts
Since 80km/h is the average speed of 92km/h and 68km/h, the power (in watts) is needed to keep the car traveling at a constant 80 km/h is P = 25299.75 watts
Answer:
2 m/s².
Explanation:
The forces acting on the crate have been shown in the figure below.
Net force acting on the crate in the horizontal direction = 400 - 250 = 150 N towards right.
For the forces of vertical direction we can write,
Normal force = 150 + Mg = 150 + 250 = 400 N (here g = 10 m/s² have been taken)
The magnitude of frictional force that will act on the crate = μ × Normal force
So, Frictional force = 0.25 × 400 = 100 N
Thus, the net force that will cause acceleration in the crate will be
Force in the right direction - frictional force
= 150 - 100 = 50 N
As we know,
Acceleration =
=
= 2 m/s²
So, the net acceleration in the crate will be 2 m/s².