Answer:
14.7 m/s
Explanation:
a = acceleration experienced by driver's head = 50 g = 50 x 9.8 m/s² = 490 m/s²
v₀ = initial speed of the driver = 0 m/s
v = final speed of the driver after 30 ms
t = time interval for which the acceleration is experienced = 30 ms = 0.030 s
Using the equation
v = v₀ + a t
Inserting the values
v = 0 + (490) (0.030)
v = 14.7 m/s
Answer:
The other angle is 30 degrees.
Explanation:
The range of projectile is given by :

Here,
u is the speed of launch of projectile
Here, 
We need to find the other launch angle when the projectile have the same range, such that,




So, the other angle is 30 degrees. Hence, this is the required solution.
Answer:
ΔLa/ΔLb = 1
Explanation:
The change in length of a solid is given by the following formula:
ΔL = α L ΔT
where,
ΔL = Change in length
α = coefficient of linear expansion
L = Original Length
ΔT = Change in Temperature
Since, the length and change in temperature for both rods are same. Also, the material of each rod is same, which implies that coefficient of linear expansion for both rods is same. Hence, the ratio of change in length of both rods will be:
<u>ΔLa/ΔLb = 1</u>
Answer:
The time rate of change in air density during expiration is 0.01003kg/m³-s
Explanation:
Given that,
Lung total capacity V = 6000mL = 6 × 10⁻³m³
Air density p = 1.225kg/m³
diameter of the trachea is 18mm = 0.018m
Velocity v = 20cm/s = 0.20m/s
dv /dt = -100mL/s (volume rate decrease)
= 10⁻⁴m³/s
Area for trachea =

0 - p × Area for trachea =



⇒

ds/dt = 0.01003kg/m³-s
Thus, the time rate of change in air density during expiration is 0.01003kg/m³-s