Answer:
<h2>a) t = 4</h2>
Explanation:
In projectile the time taken by an object to reach its maximum height is the maximum time (tmax).
tmax = Usin
/g
U = velocity of the ball
= angle of projection = 90° (vertical velocity)
g = acceleration due to gravity = 9.8m/s²
tmax = Usin90°/9.8
tmax = U/9.8
T the maximum height U = Uy = 39.2 m/s²
tmax = 39.2/9.8
tmax = 4secs
To calculate the time at which the ball will have an horizontal velocity, we will use the same formula but will be 0° in this case
If Ux = Ucos
8 = Ucos0
U = 8m/s
Since t = Usin/g
t = 8sin0/9.8
t = 0sec
Answer:
Mass = 873.6kg = 0.874 × 10^3 kg
Order = 3
Question:
Compute the order of magnitude of the mass of a bathtub half full of pennies.(Assume the pennies are made entirely of copper and the tub measures 1.3 m by 0.5 m by 0.3 m)
Explanation:
Given:
Dimensions of the tub = 1.3 m by 0.5 m by 0.3 m
Density of copper d = 8960kg/m^3
Mass = volume × density
Volume of tub = L×B×H = 1.3 × 0.5 × 0.3 = 0.195m^3
Since the tub is half full:
V = 0.195/2 = 0.0975m^3
Mass = 8960kg/m^3 × 0.0975m^3
Mass = 873.6kg = 0.874 × 10^3 kg
Order = 3
Note: Order of magnitude is of the form:
N = a × 10^b
Where;
b = order of magnitude
and
1/√10 </= a < √10
Answer:
a)
b)
Explanation:
a)
= mass of the asteroid = 43000 kg
= initial speed of asteroid = 7600 m/s
= final speed of asteroid = 5000 m/s
= Work done by the force on asteroid
Using work-change in kinetic energy theorem
b)
= magnitude of force on asteroid
= distance traveled by asteroid while it slows down = 1.4 x 10⁶ m
Work done by the force on the asteroid to slow it down is given as
<span>The net force acting on an object is the sum of all the force acting on it, and the net force of an object is zero. I f the forces acting on it tend to cancel each other. For example you are sit in a chair, the earth's gravity is pulling you down, but the chair is pushing you up with an equal amount of force.</span>
