Answer:
The the recoil velocity of the hunter is 0.056 m/s in opposite direction of the bullet.
Explanation:
Given;
mass of bullet, m₁ = 4.2 g = 0.0042 kg
mass of hunter + gun = 72.5 kg
velocity of the bullet, u = 965 m/s
Momentum of the bullet when it was fired;
P = mv
P = 0.0042 x 965
P = 4.053 kg.m/s
Determine the recoil velocity of the hunter.
Total momentum = sum of the individual momenta
Total momentum = momentum of the bullet + momentum of the hunter
Apply the principle of conservation of momentum, sum of the momentum is equal to zero.
Therefore, the the recoil velocity of the hunter is 0.056 m/s in opposite direction of the bullet.
It really depends on what the bulb is being used for, since efficiency means how much of the output is USEFUL.
If the bulb is being used for light in a dark room, then it produces (8.2% x 21W) = 1.72 joules per second of light energy.
If the bulb is being used to keep a hamster cage or a fish tank warm, then the 8.2% is the useful part, and the light is the other (91.8% x 21W) = 19.28 joules per second.
As per Newton's II law we know that
rate of change in momentum is Net outside force on the object
now here we will have if net outside force will be zero
then we can say
so from above equation we can say
and hence we have
so the correct answer will be
<em>3.) in the absence of outside forces</em>
Answer:
1.697s
Explanation:
We use the second equation of free fall under gravity as follows;
Since the ball fell freely, u = 0m/s, therefore equation (1) reduces to
Given that h is the total height the ball falls through in time t seconds.
However, according to the stated problem the ball falls halfway in 1.2s, this simply implies that the ball falls through a distance of 
in 1.2s. Hence we can write the following, given that 
;
We can now proceed to find the time t for which it falls through h = 14.112m as follows;
