F = m · a
In order to accelerate 82 kg upward at the rate of 3.2 m/s², a NET upward force of (82kg · 3.2m/s²) = 262.4 Newtons is required.
But if the object is on or near the surface of the Earth, then there's a downward force of (82kg · 9.8m/s²) = 803.6 N already acting on it because of gravity.
So you need to apply (803.6N + 262.4N) = <em>1,066 Newtons UPward</em>, in order to cancel its own weight and accelerate it upward at that rate.
Answer:
64 m
Explanation:
Using the following symbols
x: distance
v: velocity
a: constant acceleration
t: time
v₀: initial velocity
x₀: initial position
The equations of motion for a constant acceleration are given by:
(1) x = 0.5at²+v₀t+x₀
(2) v = at+v₀
From equation (2) you can calculate the time t it takes the car to come to a complete stop.
(3) t = (v-v₀)/a
Now you plug equation (3) in equation(1):
(4) x = 0.5a((v-v₀)/a)²+v₀((v-v₀)/a)+x₀
In equation (4) the position x is the only unknown.
The answer is 570 J. The kinetic energy has the formula of 1/2mV². The total work in this process W= 1/2m(V2²-V1²) = 1/2 * 15.0 * (11.5²-7.50²) = 570 J.
Answer:
1083.3kg/m
³
Explanation:
Given parameters:
Mass of aluminium ball = 3.4kg
Apparent mass of ball = 2.1kg
Unknown:
Density of the liquid = ?
Solution:
Density is is the mass per unit volume of any give substance;
Density = 
Now, we must understand that the apparent weight of the aluminium is the part of its weight supported by the fluid;
Pl = 
Pl = density of liquid
Ml = mass of liquid
Vl = volume of liquid
Mass of liquid = Mal - Mapparent
Mal = mass of aluminium
The volume of liquid displaced is the same as the volume of the aluminium according to Archimedes's principle;
Ml = Pl x Vl
Val = Vl
Val volume of aluminium
Vl = volume of liquid
****
Pal = 
Val = 
Val = volume of aluminium
Mal = mass of aluminium
Pal = density of aluminium
*****
Since the Val = Vl
Ml = Pl x 
Since
Ml = Mal - Mapparent
Mal - Mapparent = Pl x 
Pal = density of aluminium = 2712 kg/m
³
3.4 - 2.1 = Pl x 
1.3 = Pl x 0.00123
Pl = 1083.3kg/m
³
Answer:
(I). The effective cross sectional area of the capillaries is 0.188 m².
(II). The approximate number of capillaries is 
Explanation:
Given that,
Radius of aorta = 10 mm
Speed = 300 mm/s
Radius of capillary 
Speed of blood 
(I). We need to calculate the effective cross sectional area of the capillaries
Using continuity equation

Where. v₁ = speed of blood in capillarity
A₂ = area of cross section of aorta
v₂ =speed of blood in aorta
Put the value into the formula



(II). We need to calculate the approximate number of capillaries
Using formula of area of cross section


Put the value into the formula


Hence, (I). The effective cross sectional area of the capillaries is 0.188 m².
(II). The approximate number of capillaries is 