Part A. For this part, we use two equations for linear
motion:
<span>y = y0 + v0 t + 0.5 g t^2 --->
1</span>
<span>vf = v0 + g t --->
2</span>
First we solve for t using equation 1: y0 = 0 (initial
point at top), y = 250 m, v0 = 0 (at rest)
250 = 0.5 (9.8) t^2
t = 7.143 s
Now we solve for final velocity vf using equation 2:
vf = g t
vf = 9.8 (7.143)
vf = 70 m/s
Part B. First we solve for the time it takes for the sound
to reach the tourist.
t(sound) = 250 / 335 = 0.746 s
Therefore the total time would be:
t = 0.746 s + 0.300 s
t = 1.05 s
<span>Hence there is enough time for the tourist to get out
before the boulder hits him.</span>
Answer:
a. The human body has nearly the same density as salt water after exhaling.
b. The human body will always float in the Dead Sea.
Explanation:
According to the concept of floating on the basis of density, any body that is put in a fluid of density greater than its own density will always float due to the force of buoyancy from the liquid.
- The portion of the object submerged while the object is floating depends upon the density of the object as compared to the density of the fluid. This is governed by the equation:
where:
density of the fluid
density of the object
volume of the object submerged in the fluid
total volume of the object
Answer:
A projectile is an object upon which the only force is gravity. Gravity acts to influence the vertical motion of the projectile, thus causing a vertical acceleration. The horizontal motion of the projectile is the result of the tendency of any object in motion to remain in motion at constant velocity.
Explanation:
Answer:
A wave of compression and rarefaction, by which sound is propagated in an elastic medium such as air.
There are two numbers i.e (c) and (d) with 4 significant figures, since we start counting the first non-zero digit from the left, therefore, A. Has 1 significant figure, B has 5 significant figurea and C,D have 4 significant figures.
