Explanation:
Given parameters:
Initial velocity = 72km/hr
Final velocity = 0km/hr
Time taken = 25s
Unknown:
Acceleration = ?
Solution:
To solve this problem, convert km/hr to m/s;
1000m = 1km
3600s = 1hr
72km/hr;
1km/hr = 0.278m/s
72km/hr = 0.278 x 72 = 20.02m/s
Acceleration is the change in velocity divided by the time taken;
Acceleration =
Acceleration = = -0.8m/s
The car is actually decelerating at a rate of 0.8m/s
Answer:
2.5 m/s
Explanation:
The speed of the animal is given by the ratio between the distance travelled by the animal and the time elapsed:
where d is the distance travelled and t the time elapsed. Note that this quantity is also equal to the slope of the curve.
In the time interval 0-20 s, we have
d = 50 m - 0 m = 50 m
t = 20 s - 0 s = 20 s
So, the speed is
Answer:
Fe= 28.2 N : Magnitude of the equilibrant (Fe)
β = 18.34° , clockwise from the positive x axis
Explanation:
Concept of the equilibrant
It is called equilibrant to a force with the same magnitude and direction as the resulting one (in case it is non-zero) but in the opposite direction. Adding vectorially to all the forces (that is to say the resulting one) with the equilibrant you get zero
To solve this problem we decompose the forces given into x-y components to find the resulting force:
Look at the attached graphic
F₁= 33.4 N , θ₁=23.8° clockwise from the positive y axis (y+)
F₁x= 33.4 *sin23.8° = 13.48 N
F₁y= 33.4 *cos23.8° =30.6 N
F₂=46.1 N , θ₂=28.8 counterclockwise from the negative x axis (x-)
F₂x= -46.1 *cos28.8° = -40.4 N
F₂y= -46.1 *sin28.8° = -22.2 N
Components of the resultant in x-y R(x,y)
Rx= 13.48 N -40.4 N = - 26.92 N
Ry= 30.6 N -22.2 N = + 8.4 N
Components of the equilibrant in x-y Fe(x,y)
Fex= +26.92 N
Fey= - 8.4 N
Magnitude of the equilibrant (Fe)
Fe= 28.2 N
Angle the equilibrant makes with the x axis ( β)
β = -18.34°
β = 18.34° , clockwise from the positive x axis
