We have to calculate the impulse of a hockey puck.
Imp = m * ( v 1 - v 2 ) = m * Δ v
v 1 = - 10 i m/s,
v 2 = ( 20 * cos 40° ) i + ( 20 * sin 40° ) j =
= ( 20 * 0.766 ) i + ( 20 * 0.64278 ) j = ( 15.32 i + 12.855 j ) m/s
Δ v = ( 15.32 i + 12.855 j ) - ( - 10 i ) =
= 15.32 i + 12.855 j + 10 i = 25.32 i + 12.855 j
| Δv | = √ ( 25.32² + 12.855²) = √806.35 = 28.4 m/s
Imp = 0.2 kg * 28.4 m/s = 5.68 N-s
Answer: D ) 5.68 N-s.
6 meters is left because you subtract 12 meters from 6
Answer:
The weight of measuring stick is 9.8 N
Explanation:
given information:
the mass of the rock, 
= 1 kg
measuring stick, x =1 m
d = 0.25 m
to find the weight of measuring stick, we can use the following equation:
τ = Fd
τ = 0
- 
= 0
F_{r} = the force of the rock
F_{s} = the force of measuring stick
= m g
= 1 kg x 9.8 m/s
= 9.8 N
thus, the weight of measuring stick is 9.8 N
Answer:
freqiency=velocity/wavelength
ief=20/2000=0.01hz
Answer:
The speed should be reduced by 1/√2 or 0.707 times
Explanation:
The relationship between the kinetic energy, mass and velocity can be represented by the following equation:
K.E = ½m.v²
In this equation, the mass is inversely proportional to the square of the velocity or speed. This means that as the mass increases, the speed reduces by × 2.
Let; initial mass = m1
Final mass = m2
Initial velocity = v1
Final velocity = v2
According to the question, if the mass of the body is doubled i.e. m2 = 2m
½m1v1² = ½m2v2²
½ × m × v1² = ½ × 2m × v2²
Multiply both sides by 2
(½ × m × v1²)2 = (½ × 2m × v2²)2
m × v1² = 2m × v2²
Divide both sides by m
v1² = 2v2²
Divide both sides by 2
v1²/2= v2²
Square root both sides
√v1²/2= √v2²
v1/√2 = v2
v2 = 1/√2 v1
This shows that to maintain the same kinetic energy if the mass is doubled, the speed should be reduced by 1/√2 or 0.707 times.
