Answer:
The acceleration of a car would be:
m/s²
Explanation:
Given
Initial velocity =
m/s
Final velocity =
m/s
Time elapsed =
s
To determine
We need to determine the acceleration of a car.
We know that acceleration is basically the rate of change in velocity over time.
Thus,
We can determine the acceleration using the formula

where
is the acceleration
is the initial velocity
is the final velocity
is time elapsed
now substituting the values
,
, and
in the formula



m/s²
Therefore, the acceleration of a car would be:
m/s²
Answer:
19.8 J
Explanation:
According to the law of conservation of energy, the total mechanical energy of the spring (sum of kinetic energy and elastic potential energy) must be conserved:
(1)
where we have
is the initial kinetic energy of the spring, which is zero because the spring starts from rest (2)
is the elastic potential energy of the spring when it is fully stretched
is the kinetic energy of the spring when it reaches the natural length
is the elastic potential energy of the spring when it reaches its natural length, which is zero because the stretch in this case is zero (3)
So

where
k = 440 N/m is the spring constant
is the initial stretching of the spring
Substituting,

And so using eq.(1) and keeping in mind (2) and (3) we find

Answer:
Explanation:
When the box is on the ramp , component of its weight along the ramp
= mg sinθ
Friction force acting on it in upward direction
=μ mg cosθ
For sliding
μ mg cosθ < mg sinθ
μ cosθ < sinθ
.5 x cos35 < sin35
.41 < .57
So the box will slide
When sliding starts , kinetic friction acts
Net force in downward direction
mgsinθ - μ mg cosθ
acceleration
= gsinθ - μ g cosθ
= 5.62 - .3 x 9.8 x cos35
= 5.62 - 2.4
= 3.22 m /s²
<span>Let's convert the speed to m/s:
speed = (55 mph) (1609.3 m / mile) (1 hour / 3600 seconds)
speed = 24.59 m/s
Let's convert the mass to kilograms:
mass = (2135 lb) (0.45359 kg / lb)
mass = 968.4 kg
We can find the kinetic energy KE:
KE = (1/2) m v^2
KE = (1/2) (968.4 kg) (24.59 m/s)^2
KE = 292780 joules
The kinetic energy of the automobile is 292780 joules.</span>