A 2.1 times 103 - kg car starts from rest at the top of a 5.0 - m - long driveway that is inclined at 20 deg with the horizontal
. If an average friction force of 4.0 times 103 N impedes the motion, find the speed of the car at the bottom of the driveway.
1 answer:
Answer:
speed of the car at the bottom of the driveway is 3.8 m/s
Explanation:
given data
mass = 2.1× 10³ kg
distance = 5 m
angle = 20 degree
average friction force = 4 × 10³ N
to find out
find the speed of the car at the bottom of the driveway
solution
we find acceleration a by force equation that is
force = mg×sin20 - friction force
ma = mg×sin20 - friction force
put here value
2100a = 2100 ( 9.8)×sin20 - 4000
a = 1.447 m/s²
so from motion of equation
v²-u² = 2as
here u is 0 by initial speed and v is velocity and a is acceleration and s is distance
v²-0 = 2(1.447)(5)
v = 3.8
speed of the car at the bottom of the driveway is 3.8 m/s
You might be interested in
Answer:
t = 3.516 s
Explanation:
The most useful kinematic formula would be the velocity of the motorcylce as a function of time, which is:
Where v_0 is the initial velocity and a is the acceleration. However the problem states that the motorcyle start at rest therefore v_0 = 0
If we want to know the time it takes to achieve that speed, we first need to convert units from km/h to m/s.
This can be done knowing that
1 km = 1000 m
1 h = 3600 s
Therefore
1 km/h = (1000/3600) m/s = 0.2777... m/s
100 km/h = 27.777... m/s
Now we are looking for the time t, for which v(t) = 27.77 m/s. That is:
27.777 m/s = 7.9 m/s^2 t
Solving for t
t = (27.7777 / 7.9) s = 3.516 s
Answer:
8m/s^2
Explanation:
hope it helps........
There are 4 hydrogens on the right side , and 2 hydrogens on the left per molecule of
. To get the same number of hydrogens on both sides, the coefficient should be 2.
(Then the number of oxygens will be consistent, since contributes 2 oxygens, and so does
.)