Answer:
a) θ = 2500 radians
b) α = 200 rad/s²
Explanation:
Using equations of motion,
θ = (w - w₀)t/2
θ = angle turned through = ?
w = final angular velocity = 1420 rad/s
w₀ = initial angular velocity = 420
t = time taken = 5s
θ = (1420 - 420) × 5/2 = 2500 rads
Again,
w = w₀ + αt
α = angular accelaration = ?
1420 = 420 + 5α
α = 1000/5 = 200 rad/s²
Answer: 500 joules
Explanation:
Given that
Mass of ball = 10kg
kinetic energy = ?
velocity of the ball = 10m/s
Kinetic energy is the energy possessed by a moving object. It is measured in joules, and depends on the mass (m) of the object and the velocity (v) by which it moves
i.e K.E = 1/2mv²
K.E = 1/2 x 10kg x (10m/s)²
K.E = 0.5 x 10kg x (10m/s)²
K.E = 5 x 100
K.E = 500 joules
Thus, the kinetic energy of the ball is 500 joules
Answer:
the heavier skater has less momentum
hope it is helpful to you
Answer: The cylinder
Explanation:
Among all other solid shapes, the sphere has the smallest area for a given volume.
By experiment, the ratio of the radius of a sphere to a cylinder of equal volume is less than 1.
Recall;
That the Rate of transfer of convective heat (Q) = h × A ×change in temperature.
Where ,
h= the co efficient of convective heat transfer
A= the cross sectional area.
As such, since the sphere has a smaller surface area relative to the cylinder, the sphere transfers heat slower than the cylinder.
Therefore, if the sphere and cylinder are exposed to convection in the same environment, then, the cylinder cools faster.
PS; the more the Area, the higher the rate of heat transfer and vice versa.
Answer:
A) s = 796.38 m
B) t = 12.742 s
C) T = 25.484 s
Explanation:
A) First of all let's find the time it takes to get to maximum height using Newton's first equation of motion.
v = u + gt
u = 125 m/s
v = 0 m/s
g = 9.81 m/s²
Thus;
0 = 125 - 9.81(t)
g is negative because motion is against gravity. Thus;
9.81t = 125
t = 125/9.81
t = 12.742 s
Max height will be gotten from Newton's 2nd equation of motion;
s = ut + ½gt²
s = (125 × 12.742) + (½ × -9.81 × 12.742²)
s = 1592.75 - 796.37
s = 796.38 m
B) time to reach maximum height is;
t = u/g
t = 125/9.81
t = 12.742 s
C) Total time elapsed is;
T = 2u/g
T = 2 × 125/9.81
T = 25.484 s
