Answer:
We know that the second equation of motion is
S= ut + 1/2a²
And S is displacement and u is initial velocity
So in the case of Haley lets take downwards as positive Y-axis
S = 2h and
initial velocity = v
a = g (acceleration due to gravity = 9.8)
Substituting
2h = vt + 1/2gt²
And for Joe we take ownwards as positive Y-axis
S = h and
initial velocity = 0 (since the ball is dropped from rest)
a = g
h = 0x t + 1/2gt2²
t2= √ 2h/g
Now since both balls reach ground at same time: t1=t2
So
putting value of t2 in Hayley's equation:
2h= v(√2h/g) + 1/2 g( √2h/g)²
So v= √gh/2
Answer:
v = 46.67 km/h
Explanation:
We will use the following formula throughout this numerical:
s = vt
where,
s = distance covered
v = speed
t = time taken
<u>FOR FIRST 30 km:</u>
s = 30 km
v = 30 km/h
t = t₃₀ = ?
Therefore,
30 km = (30 km/h)(t₃₀)
t₃₀ = (30 km)/(30 km/h)
t₃₀ = 1 h
<u>FOR TOTAL 100 km:</u>
s = 100 km
v = 40 km/h (Average Speed)
t = total time = ?
Therefore,
100 km = (40 km/h)(t)
t = (100 km)/(40 km/h)
t = 2.5 h
<u>FOR LAST 70 km:</u>
s = 70 km
t₇₀ = t - t₃₀ = 2.5 h - 1 h = 1.5 h
v = v₇₀ = ?
Therefore,
70 km = v(1.5 h)
v = 70 km/1.5 h
<u>v = 46.67 km/h</u>
Answer:
1.18
Explanation:
The flow rate of blood is proportional to the fourth power of its radius as given the Poiseuille's law.
The law is :
It is given here that the flood flow rate is been reduced to half its normal value. Therefore,
So, for the radius and , the ratios of their flow rates are :
It is given that the flow rate is reduced to half. So we have,
or
So the radius changes by a factor of 1.18
Answer:
The magnitude of change in momentum is (2mv).
Explanation:
The momentum of an object is given by the product of mass and velocity with which it is moving.
Let the mass of ball is m. A tennis player smashes a ball of mass m horizontally at a vertical wall. The ball rebounds at the same speed v with which it struck the wall.
Initial speed of the ball is v and final speed, when it rebounds, is (-v). The change in momentum is given by :
p = final momentum - initial momentum
So, the magnitude of change in momentum is (2mv).
Answer:
Explanation:
In order to answer this question, we simply have to refer to the laws of the equations of gravitational mechanics.
The equation given by Newton tells us that
In the case where we compare a specific place where the Force of Gravity is greater or lesser, we focus on the term assigned to the Planet's Radius.
In the case of , we understand that they are constant.
We can easily notice that the more the Radius (Height seen from a viewer on the ground), the lower the force will be.
In other words, the smaller the radius in which the measurement is made with respect to the center of the earth, the greater the gravitational force.
In that order of ideas the smallest radio has South Pole, which is about 6356 km from the center of the Earth on the Equator line