. The average human walks at a speed of 5 km per hour. If your PE teacher asks you to walk for 30 minutes in
1 answer:
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Answer:
Explanation:
Given that,
Mass of cabinet, m = 45 kg
Two horizontal force of 25 newtons and 18 newtons respectively in the same direction.
When the forces are acting in same direction, the net force is equal to the sum of forces i.e.
F = 25 N + 18 N = 43 N
Let a is the aceleration of the cabinet
So,
F = ma
So, the acceleration of the cabinet is .
Answer:
a) 147.95 Mpc
Explanation:
Using Hubble's formula
where;
v = radical velocity
= Hubble's constant
d = distance
Given that:
The average radial velocity of galaxies in the Hercules cluster v = 10,800 km/s
Also using = 73 km/s/ Mpc ; we make distance d the subject of the formula:
Then distance d can be written as:
d = 147.95 Mpc
b)
Now, if the Hubble constant had a smaller value, then for a given velocity the distance to the galaxy will increase because distance d is inversely proportional to
i.e
d ∝
Refer to the diagram shown below.
Given:
R = 6.37 x 10⁶ m, the radius of the earth
h = 3.58 x 10⁷ m, the height of the satellite above the earth's surface.
Therefore
R + h = 4.217 x 10⁷ m
In geosynchronous orbit, the period of rotation is 1 day.
Therefore the period is
T = (24 h)*(60 min/h)*(60 s/min) = 86400 s
The angular velocity is
ω = (2π rad)/(86400 s) = 7.2722 x 10⁻⁵ rad/s
Part (a)
The tangential speed is
v = (R+h)*ω
= (4.217 x 10⁷ m)*(7.2722 x 10⁻⁵ rad/s)
= 3066.7 m/s
= 3.067 km/s
Part (b)
The centripetal acceleration is
a = v²/(R+h)
= (3066.7 m/s)²/(4.217 x 10⁷ m)
= 0.223 m/s²
Answers:
(a) The speed is 3.067 km/s
(b) The acceleration is 0.223 m/s²
Given:
R = 6.37 x 10⁶ m, the radius of the earth
h = 3.58 x 10⁷ m, the height of the satellite above the earth's surface.
Therefore
R + h = 4.217 x 10⁷ m
In geosynchronous orbit, the period of rotation is 1 day.
Therefore the period is
T = (24 h)*(60 min/h)*(60 s/min) = 86400 s
The angular velocity is
ω = (2π rad)/(86400 s) = 7.2722 x 10⁻⁵ rad/s
Part (a)
The tangential speed is
v = (R+h)*ω
= (4.217 x 10⁷ m)*(7.2722 x 10⁻⁵ rad/s)
= 3066.7 m/s
= 3.067 km/s
Part (b)
The centripetal acceleration is
a = v²/(R+h)
= (3066.7 m/s)²/(4.217 x 10⁷ m)
= 0.223 m/s²
Answers:
(a) The speed is 3.067 km/s
(b) The acceleration is 0.223 m/s²