Answer:
<em>a = 7.6\ mph/s</em>
Explanation:
<u>Motion With Constant Acceleration </u>
It's a type of motion in which the velocity of an object changes uniformly in time.
The equation that describes the change of velocities is:
Where:
a = acceleration
vo = initial speed
vf = final speed
t = time
Solving the equation [for a:
The car accelerates from vo=0 to vf=60 mph in t=7.9 s, thus the acceleration is:
a = 7.6\ mph/s
Answer:
The compression in the spring is 5.88 meters.
Explanation:
Given that,
Mass of the car, m = 39000 kg
Height of the car, h = 19 m
Spring constant of the spring,
We need to find the compression in the spring in stopping the ore car. It can be done by balancing loss in gravitational potential energy and the increase in elastic energy. So,
x is the compression in spring
So, the compression in the spring is 5.88 meters.
Explanation:
From the Newton's velocity of sound relationship , the velocity of sound is directly proportional to the square root of temperature .
In this case The velocity of sound = frequency x wavelength
= 798 x 0.48 = 383 m/sec
Suppose the temperature at this time = T K
Thus 383 ∝ I
The velocity of sound is 329 m/s at 273 K ( given )
Thus 329 ∝ II
Dividing I by II , we have
=
or = 1.25
and T = 339.8 K = 66.8° C