Answer:
Explanation:
given,
width of door dimension = 1 m
mass of door = 15 Kg
mass of bullet = 10 g = 0.001 Kg
speed of bullet = 400 m/s
a) from conservation of angular momentum
Answer:
N = 6.67 N
Explanation:
The frictional or frictional force is a force that arises from the contact of two bodies and opposes movement.
The friction is due to imperfections and roughness, mainly microscopic, that exist on the surfaces of the bodies. Upon contact, these roughnesses engage with each other making movement difficult. To minimize the effect of friction, either the surfaces are polished or lubricated, since the oil fills the imperfections, preventing them from snagging.
As the frictional force depends on the materials and the force exerted on one another, its magnitude is obtained by the following expression:
f = μ*N Formula (1)
where:
f is the friction force (N)
μ is the coefficient of friction
N is the normal force (N)
Data
f = 0.2 N : frictional force between the steel spatula and the Oiled Steel frying pan
μ = 0.03 :coefficient of kinetic friction between the two materials
Calculating of normal force
We replace data in the formula (1)
f = μ*N
0.2 = 0.03*N
N = 0.2 / 0.03
N = 6.67 N
Answer: T= 715 N
Explanation:
The only external force (neglecting gravity) acting on the swinging mass, is the centripetal force, which. in this case, is represented by the tension in the string, so we can say:
T = mv² / r
At the moment that the mass be released, it wil continue moving in a straight line at the same tangential speed that it had just an instant before, which is the same speed included in the centripetal force expression.
So the kinetic energy will be the following:
K = 1/2 m v² = 15. 0 J
Solving for v², and replacing in the expression for T:
T = 1.9 Kg (3.97)² m²/s² / 0.042 m = 715 N
Answer:
434 Hz
Explanation:
According to the Doppler effect, when a source of a wave is moving towards an observer at rest, then the observer will observe an apparent frequency which is higher than the original frequency of the source.
In this situation, Tina is driving towards Rita. Tina is the source of the sound wave (the horn), while RIta is the observer. Since the original frequency of the sound is 400 Hz, Rita will hear a sound with a frequency higher than this value.
The only choice which is higher than 400 Hz is 434 Hz, so this is the frequency that Rita will hear.
The electrical symbols are very important especially when fixing electrical appliances because it tells you where the wire of neutral and live go.