Answer:
time taken with speed 23 km/h will be 1.8 hours or 1 hour 48 minutes
Explanation:
Given:
Time is inversely proportional to the speed
mathematically,
t ∝ (1/r)
let the proportionality constant be 'k'
thus,
t = k/r
therefore, for case 1
time = 3 hr
speed = 14 km/hr
3 = k/14
also,
for case 2
let the time be = t
r = 23 km/h
thus,
we have
t = k/23
on dividing equation 2 by 1
we get
or
or
t = 1.8 hr = or 1 hour 48 minutes ( 0.8 hours × 60 minutes/hour = 48 minutes)
The force of frictions is opposed to relative motion.
The acceleration of the crate is approximately <u>2.937 m/s²</u>.
Reason:
The given parameters are;
The mass of the wood, m = 100 kg
The force which can move the wood, F = 588 N
Wood on wood static friction, = 0.5
Wood on wood kinetic friction, = 0.3
Solution;
The force of friction, , acting when the crate is moving is given as
follows;
= m × g ×
Where;
g = The acceleration due to gravity ≈ 9.81 m/s²
Therefore, we have;
= 100 × 9.81 × 0.3 = 294.3
The force of friction, = 294.3 N
The force with which the crate moves, F = 588 - 294.3 = 293.7
The force with which the crate moves, F = 293.7 N
Force = Mass, m × Acceleration, a
Therefore;
The acceleration of the crate, a ≈ <u>2.937 m/s²</u>.
Learn more about friction here: