Explanation:
When bullet is shot towards the monkey then let say the distance of monkey from the bullet is "d"
so we can find the time to reach the bullet to the monkey

Now similarly we can find the vertical displacement of the bullet in the same time


so it is given as

here if the monkey is initially at height H above the ground at given angle then we can say

so we can say that

So if at the same time monkey will fall down then the height of monkey from ground after time "t" is given as

so here bullet will hit the monkey as both monkey and bullet are at same position.
Translating the first sentence into equation we get, t = k(1/h)
where t is time in seconds, k is the constant and h is the horsepower. Substituting
the values in the equation we have, 12s = k(1/200) we have a k = 2400 seconds –
hp. To get the time at 240 hp we use the equation above and the constant, we
get, t = (2400 seconds-hp)(1/240hp) t = 10seconds.
Answer:
The Answer is blue
Answer:
a)- 1.799 rad/sec²
b)- 17.6 x 10ˉ³Nm
Explanation:
ω₀ = 720 rev/min x (1 min/60 sec) x (2π rad / 1 rev) = 24π rad/s
a) Assuming a constant angular acceleration, the formula will be
α = (ωf -ω₀) / t
As final state of the grindstone is at rest, so ωf =0
⇒ α = (0-24π) / 41.9 = - 1.799 rad/sec²
b)Moment of inertia I for a disk about its central axis
I = ½mr²
where m=2kg and radius 'r'= 0.099m
I = ½(2)(0.099²)
I = 9.8 x 10ˉ³ kgm²
Next is to determine the frictional torque exerted on the grindstone, that caused it to stop, applying the rotational equivalent of the Newton's 2nd law:
τ = I α =>(9.8 x 10ˉ³)(- 1.799)
τ = - 17.6 x 10ˉ³Nm
(The negative sign indicates that the frictional torque opposes to the rotation of the grindstone).