If your speed changes from 10 km/h to 6 km/h then
you have an acceleration.
Whether it's a positive or negative one completely depends
on which direction you decided to call the positive direction,
when you started considering your speed and its changes.
If you decided to call the direction in which you're traveling
the positive direction, then a decrease in your speed is a
negative acceleration.
But you could just as easily have said that you're traveling
in the negative direction. If you did that, then a decrease in
your speed would be a positive acceleration.
It's completely up to you, and how you define things.
Answer:
<h2>1.75 N</h2>
Explanation:
The force acting on an object given it's mass and acceleration can be found by using the formula
force = mass × acceleration
From the question we have
force = 3.5 × 0.5 = 1.75
We have the final answer as
<h3>1.75 N</h3>
Hope this helps you
<h2>
Depth of river is 4.48 m</h2>
Explanation:
Discharge = Area x Velocity
Discharge of river = Discharge of stream 1 + Discharge of stream 2
Area of stream 1 = w₁ x d₁ = 8.9 x 3.8 = 33.82 m²
Area of stream 2 = w₂ x d₂ = 6.5 x 3.9 = 25.35 m²
Velocity of stream 1 = 2.3 m/s
Velocity of stream 2 = 2.6 m/s
Velocity of river = 3 m/s
Substituting
Depth of river = 4.48 m
Answer:
speed is 4/3 × g × sin β
acceleration is g sin θ
Explanation:
Given data
mass = M
radius = R
distance = s
angle = β
to find out
final speed and the acceleration
solution
we know that cylinder is rolling on inclined plane
so from conservation of mechanical energy
energy at top = energy at bottom
energy at top will be
= m ×g×h
= m ×g×s sinβ ................1
and
energy at bottom will be
= 1/2 ×m × v² + 1/2 × z × ω²
= 1/2 ×m × v² + 1/2 × 1/2 ×m× r² × (v/r)²
= 3/4 × v² .................2
equating now equation 1 and 2
m ×g×s sinβ = 3/4 × v²
so v = 4/3 × g × sin β
so speed is 4/3 × g × sin β
and acceleration is
= mg sin θ ............3
and
acceleration = ma ............4
now equation equation 3 and 4
ma = mg sin θ
so acceleration is g sin θ
